Broadcast Media Terms

Affiliate: A station associated with a network by contract to broadcast the network's programs

Air Date: The first broadcast of a commercial; also refers to the exact date of a particular TV or radio program.

Audilog: The diary used by household members in Nielsen's local rating sample which records what stations and programs they viewed during a week's time.

Availability (“avails”): Unsold units of time available for broadcasters to sell to advertisers. Also refers to a station's submission of programs and rating estimates for advertising planning and buying.

Average Quarter-Hour Rating: The audience estimate reported by Nielsen and Arbitron for television and radio. It provides the average number of persons or households who watched/listened for at least 5 minutes of the 15 minute segment being reported.

Bonus Spot: Additional TV or radio spot provided to an advertiser at no charge to raise the overall audience delivery of the schedule.

Break Position: A broadcast commercial aired between two programs instead of in the middle of one program.

Broadcast Calendar: An industry-accepted calendar used mainly for accounting and billing purposes. Weeks run Monday-Sunday, and each month is four or five weeks long.

Cable TV: TV programming that is delivered by coaxial cable rather than over the air for the purposes of improved reception and delivery of additional program choices beyond the local stations.

Clearance: A station's agreement to carry a particular program.

Cut-In: A commercial inserted by the local station that covers the commercial airing at the same time on the network at the advertiser's request. Useful for testing different copy in a limited geography.

Daypart: One of the time segments into which the day is divided by broadcast media, determined by type of programming and who provides it (network or local).

Designated Market Area (DMA): Nielsen's term for geographical areas made up of exclusive counties based on which home market stations receive the predominant share of viewing.

Diary: An instrument for measuring viewing, listening or reading of media vehicles kept by people in a sample.

Drive Time: The dayparts used in radio to signify primary listening being done in cars. Generally considered to be Monday-Friday 6- 10 a.m. and 3-7 p.m. HUT-(Households Using Television) - a broadcast research term indicating the percent of homes with sets on during a specific time period.

Infomercial: A long (more than two minutes) commercial providing extensive product/service description and sales information.

Log: Chronological record of a station's program and commercial exact air times.

Network: Two or more stations joined by a line to broadcast the same program from a few original studios simultaneously.

Network Affiliate: A television or radio station that designates a portion of its air time for network programs.

Overnights: Audience data provided by Nielsen or Arbitron to metered market clients the day after the broadcast.

Pay Per View: A type of Pay TV where viewers are charged each time they watch the special event or movie being broadcast.

Pay TV: A TV system providing programs which are available only to the households who subscribe, usually transmitted via coaxial cable or telephone lines. Also called "premium channels" on cable, such is HBO, Cinemax, Showtime, Disney Channel, etc.

Persons Using Radio (PUR): The percent of the area's population listening to radio at a specific time.

Piggyback: Back-to-back scheduling of two or more brand commercials of one advertiser in network or spot positions.

Pilot: A sample of a proposed television series.

Pocketpiece: Nielsen's weekly reports providing audience estimates for all network and syndicated programs.

Pre-emption: The substitution of one advertiser's local TV commercial by another advertiser paying a higher price for the spot, or by a different program of interest.

R.O.S. (Run Of Schedule or Run Of Station): A broadcast schedule, similar to R.O.P. where specific programs and air times have not been requested by the advertiser.

Simulcast: Broadcast of the same program at the same time on both AM and FM radio stations. Can also refer to a radio station simultaneously broadcasting the audio portion of a TV program.

Strip: A program scheduled at the same time each day, typically Monday-Friday.

Superstation: An independent station whose signal is transmitted to many markets via a satellite.

Sweeps: The four 4-week periods when all TV markets are measured by Nielsen and Arbitron for station viewing and demographic information. Sweep months are February, May, July and November.

Syndicated Program: A program bought by a station or advertiser from an independent organization, not a network.

Total Audience Plan (TAP): A radio schedule consisting of equal distribution of commercials across all major dayparts.

Turnover: The ratio of a cumulative audience to the average audience for a given period of time. Indicates how loyal a given audience may be for specific stations or programs.

Upfront: A term indicating that an advertiser has purchased advertising for the coming broadcast year in an early buying season, typically for the benefit of lower rates and CPM guarantees.

General Media Terms

Advertising Impressions: The audience delivery of media vehicles, programs or schedules. Usually expressed as thousands (000).

Advertising Weight: The level of advertising support over a period of time, expressed in gross rating points, impressions, target audience reached, etc.

Average Frequency: The number of times the average person or household is exposed to an advertising schedule. It is always derived from Gross Rating Points and Reach.

Barter: A term used to indicate that advertising was paid for by the advertiser using goods and services rather than cash.

Brand Development Index: A measure of the strength of a brand's sales in a particular geographic area indexed to the national sales average.

Category Development Index (CDI): A measurement of a brand's sales potential using sales of all brands within a category in a specific market indexed to national sales average.

Clutter: The term given to the proliferation of advertising messages aimed at consumers. In TV, it refers to all nonprogram minutes, such as commercials, station promotions, billboards, public service announcements, etc.

Cost-Per-Action (CPA): Metric for assessing advertising expenditure determined by dividing the total cost for a certain advertisement by how many people actually responded (e.g., purchase activity, phone inquiries, website traffic, etc.) within a specified time after the promotion was delivered.

Cost Per Rating Point (Cost Per Point, CPP, Cost Per GRP): The cost to reach one percent of the universe, households or individuals, in a given market or geographic area.

CPTI (Cost-Per-Targeted-Impression): Metric for assessing advertising expenditure determined by dividing the total cost for a certain advertisement by the percentage of an audience who experience the advertisement (e.g., seen, heard) are actually within the marketer’s target market.

Cost Per Thousand (CPM): The cost to reach 1,000 units of audience, households or individuals, for advertising. Used as a measure of efficiency among media and media schedules.

Coverage Area: The specific geography where a media vehicle has its coverage. In broadcast, coverage usually describes the area to which the station's signal extends. In print, coverage usually means the circulation area.

Cume (Cumulative Audience): Another way of expressing reach. The total number of different people or households exposed to advertising at least once during the media schedule.

Direct Mail Marketing: A mailed advertisement that is addressed to specific individuals, rather than a blanket mailing over a geographic area.

Direct Response Advertising: Any advertising message that calls for a prompt response to purchase a product or request more information.

Duplication: The number or percent of the target audience in one media vehicle also exposed to another vehicle.

Efficiency: The ratio of cost to size of audience used to compare media vehicles, plans or schedules.

Exact Time: Provided by media owners on the actual Invoice/Affidavit. This is the final and official reported time of commercial airing and supersedes any previous reported Pre or Post Log times. For all intensive purposes, this is the time the spot aired.

Exclusivity: An agreement whereby a media vehicle agrees to run no advertising directly competitive to the advertiser purchasing the media vehicle or program.

First Refusal: The opportunity for an advertiser to extend sponsorship rights of a program or vehicle before it is offered to another advertiser.

Fixed Position: An advertising position which remains fixed over time, such as the inside cover of a magazine.

Flighting: A technique for extending advertising dollars using periods of media activity interspersed with periods of inactivity.

Gross Impressions: The combined audiences of several media vehicles or several announcements within a vehicle, leaving in the duplication among the audiences.

Gross Rating Points (GRP's): The sum of individual ratings in a media plan.

Guarantee: A commitment to the advertiser by a medium that should audience delivery fall short of what was estimated, the advertiser will receive bonus advertising to meet the expected CPM or GRP's.

Impression: An impression is the number of times your ads were shown across various media, i.e. TV, Radio, Internet advertising, etc.

Heavy-up: An increase in advertising activity for a limited period of time.

Hiatus: A scheduled period of inactivity between advertising flights.

Little America (or Little U.S.): Refers to the method of media testing where a national campaign might be tested first in markets that are most similar demographically to the total country.

Makegood: Comparable unit of advertising offered at no charge when the original spot or ad did not run or ran incorrectly.

Mediamark Research Inc. (MRI): A syndicated research source measuring print and broadcast media audiences and product/brand usage profiles.

Net Cost: Advertising rates which do not include advertising agency commission and/or include discounts.

Penetration: The degree to which a medium or vehicle has coverage in a specific area. Can also refer to the effectiveness of advertising's impact on consumers.

Per Inquiry (P.I.): Agreement between a media owner and an advertiser where the advertiser pays the owner for advertising on the basis of the number of inquiries or completed sales from the advertising.

Post-Log Time: Again, provided from media owners, this is an estimated time based on the Log data that a commercial/spot ran. Usually available 24-48 hours after airing. Although this data is from the Master Log, it is not 100% accurate.

Pre-Log Time: Provided from stations, cable systems, networks, this is an estimated time a commercial/spot will air in the future based on Pre-log data. Available a week out, a few days or the day before airing (sometimes the day of). The Pre-log time reported closest to the airing is the most accurate but is in fact an estimated time.

Psychographic: Describes consumers on the basis of some psychological trait, characteristics or life style.

Quintile: The division of the audience or sample into five equal groups ranging from heaviest to lightest amount of exposure to any medium.

Rate Card: A statement by a medium showing advertising costs, issue dates, program names, closing dates, requirements, cancellation dates, etc.

Rating: An estimate of the size of an audience expressed as one percent of the total population.

Return on Investment (ROI): A measure of operating performance and efficiency in using assets computed by dividing net income by average total assets.

Reach: The unduplicated percent of a potential audience exposed to advertising one or more times during a given period.

Roll Out: An advertising technique where advertising is expanded to cover more and more markets as distribution/ product sales are also expanded.

Share: The percent of an audience tuned to a particular program at a given time.

Share of Voice (SOV): A brand's percent of the total advertising weight in its product category.

Short Rate: The cost difference between the discounted contract rate and the higher rate actually earned by an advertiser if he fails to fulfill the contracted amount of advertising.

Simmons Market Research Bureau (SMRB): A syndicated source of print and broadcast audience measurement, as well as product usage data.

Sponsorship: Purchase of all or part of a TV program or all pages of a magazine.

Standard Rate & Data Service (SRDS): Monthly reports of publications', TV and radio stations' rate cards and supporting technical information arranged by state and market.

Vehicle: Anything capable of exposing advertising to customers.

Internet Media Terms

Browser: An application used to view and navigate the World Wide Web and other Internet resources.

Chat: A form of interactive online communication that enables typed conversations to occur in real-time. When participating in a chat discussion, your messages are instantaneously relayed to other members in the chat room while other members' messages are instantaneously relayed to you.

Chat History: A transcript of a chat session.

Cost-Per-Click (CPC): Unique to internet advertising, this is the fee paid to the web publisher each time a visitor clicks on an internet ad.

Click: A click is when a visitor interacts with an advertisement by clicking on the ad itself. In the AdMob user interface, a click refers to the total number of times a group of ads or an individual ad has received clicks.

Click-Through Rates: The number of times a web page ad is clicked on as a percentage of the number of times the web page ad is displayed.

Commercial Online Service: A computer network that supplies its members with access to chat rooms, bulletin boards, and other online content on a monthly fee basis. Commercial online services include America Online, CompuServe, The Microsoft Network, and Prodigy. In addition to their own proprietary content, most commercial online services also provide access to the Internet.

Congestion: A state occurring in a part of a network when the message traffic is so heavy that it slows down network response time.

Connection: When two computers have established a path through which the exchange of information can occur.

Cookies: Small files that are downloaded to your computer when you browse certain web pages. Cookies hold information that can be retrieved by other web pages on the site. Some cookies are programmed with an expiration date so that they are automatically deleted after a period of time.

Copy Protection: A software lock placed on a computer program by its developer to thwart piracy. This preventative measure was widely used in the mid-1980s but later abandoned by many developers because of numerous customer complaints.

Cracker: A malicious hacker who breaks (or cracks) the security of computer systems in order to access, steal, or destroy sensitive information. “Hacker” is often incorrectly used instead of cracker, especially by the media. See also hacker.

Crossload: To send an attached file via email. See also upload and download.

Domain Name: The official name of a computer connected to the Internet. Domain names are derived from a hierarchical system, with a host name followed by a top-level domain category. The top-level domain categories are com (for commercial enterprises), org (for non-profit organizations), net (for network services providers), mil (for the military), and gov (for government).

Domain Name System (DNS): A database system which looks up host IP addresses based upon domain names. For example if you ask for "www.thisismyhost.com" it will return 123.45.67.89. Copies of the Domain Name System are distributed through the Internet.

Download: To transfer data from a larger "host" system to a smaller "client" system's hard drive or other local storage device. See also upload.

Download Charges: onetary charges associated with downloading a file from a commercial online service. This method of information exchange is not very popular.

Ecash: Electronic money designed to be used over a network or stored on cards similar to credit cards. Ecash is still more of an idea than a practical reality, largely due to security concerns.

Eform: An electronic form that is filled out by a user and sent over a network. They are typically used to place orders or provide feedback. Eforms can be placed on web pages or in Java applets and usually contain text boxes, buttons, and other components.

Encryption: A procedure that renders the contents of a message or file unintelligible to anyone not authorized to read it. PGP (Pretty Good Privacy) is a commonly-used encryption program.

Eyeballs: A viewing audience for a WWW site.

Facilitated Chat: In a facilitated chat, a host or facilitator controls the messages that appear on the chat screen. Usually used when there is a guest speaker. Facilitated chats provide an orderly environment for the guest speaker and ensure that she is not overwhelmed with dozens of questions all being asked at once.

Flame: A public post or email message that expresses a strong opinion or criticism. Flames can be fun when they allow people to vent their feelings, than return to the topic at hand. Others are simply insulting and can lead to flame wars.

Flame Bait: An inflammatory post that is designed to provoke a flame war or flame responses.

Flash Session: A feature of America Online that automatically performs online tasks at a designated time. Flash sessions are often used to send/receive email and download large files.

Forum: A topically-focused discussion group or area. From the traditional Roman forum.

Go Word: The word associated with a forum or area on a commercial online service that allows you to get to that place quickly.

Hacker: An expert programmer who likes to spend a lot of time figuring out the finer details of computer systems or networks, as opposed to those who learn only the minimum necessary. See also cracker

Hit: A single user accessing a single file from a web server. A unit of measure often used erroneously to evaluate the popularity of a web site.

Home Page: A web page that is topically the main source of information about a particular person, group, or concept. Many people on the web create home pages about themselves for fun; these are also known as vanity pages.

Host:

- A computer that allows users to communicate with other host computers on a network.

- A chat term for someone who is managing a chat. Hosts often act as referees and have the power to turn participants into spectators and vice versa.

Hyperlink: A highlighted word or picture within a hypertext document that when clicked takes you to another place within the document or to another document altogether.

Hypertext: Text that includes links or shortcuts to other documents, allowing the reader to easily jump from one text to related texts, and consequentially from one idea to another, in a non-linear fashion. Coined by Ted Nelson in 1965.

Hypertext Markup Language (HTML): The tag-based ASCII language used to create pages on the World Wide Web. See also hypertext.

Hypertext Transfer Protocol (HTTP): The protocol used by the World Wide Web to transfer HTML files.

Icon: A small graphic image that represents a file or application and when clicked upon produces a programmed result. Use of this mnemonic convention originated at Xerox PARC and was subsequently popularized by the Apple Macintosh. Producing an effective icon is non-trivial because of size and color restraints. See iconographer.

Iconographer: A skillful designer who elevates icon design to an art form.

Identity Hacking: Posing as someone else. Posting anonymously or pseudonymously, usually with the intent to deceive.

Infobahn: A variant of information superhighway. An unimplemented proposal by Vice President Al Gore to wire the US for hundreds of cable television channels. Now synonymous with the Internet.

Integrated Services Digital Network (ISDN): A technology offered by telephone carriers that allows for the rapid transfer of voice and data.

Internet: A worldwide network of networks that all use the TCP/IP communications protocol and share a common address space. First incarnated as the ARPANET in 1969, the Internet has metamorphosed from a military internetwork to an academic research internetwork to the current commercial internetwork. It commonly supports services such as email, the World Wide Web, file transfer, and Internet Relay Chat. The Internet is experiencing tremendous growth in the number of users, hosts, and domain names. It is gradually subsuming other media, such as proprietary computer networks, newspapers, books, television, and the telephone. Also known as “the net”, “the information superhighway”, and “cyberspace.”

Internet Explorer: A free web browser application from Microsoft.

Internet Relay Chat (IRC): A chat network that operates over the Internet. Originally evolved from the UNIX talk program, IRC is similar to the chat systems found on commercial online services.

Internet Service Provider (ISP):

- A business that delivers access to the Internet, usually for a monthly fee. PSI, UUNET, and Netcom are examples of established ISPs but there are thousands of smaller ones all around the world.

- Any business that provides Internet services such as web sites or web site development.

Internet Society (ISOC): To quote its home page at http://info.isoc.org: “The Internet Society is a non-governmental International organization for global cooperation and coordination for the Internet and its internetworking technologies and applications.”

Intranet: A private network that uses Internet-related technologies to provide services within an organization.

IP address: A string of four numbers separated by periods (such as 111.22.3.444) used to represent a computer on the Internet. The format of the address is specified by the Internet Protocol in RFC 791. When a PC accesses the Internet through an ISP, it sometimes receives a temporary IP address.

Jack In: To log in to a machine or connect to a network. Derived from cyberpunk fiction.

Java: An object oriented programming language created by Sun Microsystems. Java is a device independent language, meaning that programs compiled in Java can be run on any computer. Java programs can be run as a free-standing application or as an applet placed on a web page. Applets written in Java are served from a web site but executed on the client computer. Java applets have a built-in security feature which prevents them from accessing the file system of the client computer.

JavaScript: A scripting language that allows lines of Java code to be inserted into HTML scripts.

Joint Photographic Experts Group (JPEG): An image compression standard for still photographs that is commonly used on the web.

Link: A highlighted word or picture within a hypertext document that when clicked bring you to another place within the document or to another document altogether. See also hyperlink.

List Server: An automated mailing list distribution system. List servers maintain a list of email addresses to be used for mass emailing. Subscribing and unsubscribing to the list is accomplished by sending a properly formatted email message to the list server.

Local Area Network (LAN): A group of computers at a single location (usually an office or home) that are connected by phone lines or coaxial cable.

Mailbomb: The act of sending massive amounts of email to a single address with the malicious intent of disrupting the system of the recipient. Mailbombing is considered a serious breach of Netiquette and is probably illegal.

Mailing List: A discussion group that occurs via mass email distributions. Mailing lists are usually maintained by individuals utilizing list server software. List servers maintain a list of email addresses to be used for the mailing list. Subscribing and unsubscribing to the list is accomplished by sending a properly formatted email message to the list server.

Mirror Site: A server which contains a duplicate of another WWW or FTP site. Mirror sites are created when the traffic on the original site becomes too heavy for a single server. Often mirror sites are located in different geographic areas allowing users to choose the site closest to them.

Navigator: A web browser application from Netscape.

Net Lingo: The slang commonly used on the Internet.net.police. Those who feel it's their appointed role to flame perceived violations of Netiquette.

Net Surfing: Browsing or exploring a network or the World Wide Web to find places of interest, usually without a specific goal in mind. Analogous to channel surfing with a TV remote control.

Netiquette: Network etiquette, or the set of informal rules of behavior that have evolved in Cyberspace, including the Internet and online services.

Netlag: A condition that occurs on the Internet in which response time is greatly slowed due to heavy traffic.

Netnews: The content of USENET.

Network: A group of computers or devices that are connected together for the exchange of data and sharing of resources.

Newsgroup: A public place where messages are posted for public consumption and response. The most available distribution of newsgroups is USENET which contains over ten thousand unique newsgroups covering practically every human proclivity. The names of newsgroups are comprised of a string of words separated by periods, such as “rec.humor.funny” or “misc.jobs.offered”. The first word (i.e. “rec” or “misc”) represents the top level category of newsgroups. The second word (in these examples “humor” and “jobs”) represents a subcategory of the first level, and the third word a subcategory of the second.

Non-Disclosure Agreement (NDA): A contract commonly used by computer companies to protect the confidentiality of unreleased products. Software developers, reporters, and sometimes beta testers are often required to sign these before they are given access to either information about upcoming products or the product itself.

Offline:

- As an adjective, not connected to a computer network.

- As an adverb, not here or not now, as in “Let's take this discussion offline.” Often used to indicate that a topic should be discussed privately rather than in a public forum.

Online:

- Currently connected to a host, opposite of offline.

- Referring to anything connected to a computer network.

Password: A secret code that you utilize along with your user ID in order to log on to a network.

Path: The hierarchical description of where a directory, folder, or file is located on your computer or on a network

Post: To send a message to a public area like a BBS or newsgroup where it can be read by many others.

Postmaster: The name given to the person in charge of administrating email for a particular site. According to convention, mail sent to postmaster@foo.com should be read by a real live person. Protocol|A series of rules and conventions that allow different kinds of computers and applications to communicate over a network.

Query:

- A general question posed to a person or group over the Internet.Internet users are generally so helpful that if one asks an appropriate query to the correct discussion group, one will often receive many useful responses. One caveat: it is necessary to find and read the appropriate FAQ document first. Failure to do so would be considered a waste other people's time and bandwidth.

README File:

- A text file included with an application that contains important (and often last minute) information about installing and using the application.

- A text file on an FTP site that provides valuable information about the context of site.

- Any text file that you are supposed to read before proceeding.

Run-of-network (RON): A run-of-network ad is characterized as an ad that is set to run on all sites or apps within a given network without any specified targeting selections.

Search Engine: A program or web site that enables users to search for keywords on web pages throughout the World Wide Web. For example, Google is a popular search engine located at http://www.google.com.

Search Engine Marketing (SEM): A form of Internet marketing that seeks to promote websites by increasing their visibility in search engine result pages (SERPs) through the use of paid placement, contextual advertising, and paid inclusion.

Search Engine Optimization (SEO): Also known as SEO, search engine optimization is simply making your website easier to find over the internet. When you choose a web designer to construct your business’ website be sure to discuss SEO with him/her to help make your business more accessible over the web.

Security: Ensuring that private information remains private in an atmosphere where all other information is free. Security also means that viruses are prevented from infecting people's systems.

Server: A computer that provides information to client machines. For example, there are web servers that send out web pages, mail servers that deliver email, list servers that administer mailing lists, FTP servers that hold FTP sites and deliver files to users who request them, and name servers that provide information about Internet host names.

Shareware: Software that you can download from a network and “try before you buy.” If you like the software and decide to use it beyond the trial period, you must register with the author and pay a registration fee.

Shouting: TYPING IN ALL CAPITAL LETTERS IS CONSIDERED SHOUTING IN ONLINE COMMUNICATIONS.

Snail Mail: Regular postal mail, as opposed to email. Pejorative when implying postal mail's slowness relative to email.

Sneakernet: The transfer of electronic information by physically carrying disks, tape, or some other media from one machine to another. Used ironically.

Spam: To send a message (usually an advertisement) to many discussion groups (bulletin boards, mailing lists, and/or newsgroups), without regard for its topical relevance.

Telecommunications: The science of sending signals representing voice, video, or data through telephone lines.

Telecommuting: To work at home and use a computer and modem to communicate with the office.

Telnet: A protocol which allows you to sign onto a remote UNIX computer from a another computer located anywhere on the Internet. To telnet into a remote computer, you usually need to supply a user ID and password that is recognized by the remote system.

Thread:

- A series of postings on a particular topic. Threads can be a series of bulletin board messages (for example, when someone posts a question and others reply with answers or additional queries on the same topic). A thread can also apply to chats, where multiple conversation threads may exist simultaneously.

-Also refers to an independent process taking place in a multi-tasking environment.

Toggle:

- A switch that is either on or off.

- If it is on, to turn it off; if it is off, to turn it on.

Traffic: The load of packets carried by a network or portion of a network. Heavy traffic slows down the response time of the individual packets.

Triple-dub: An abbreivated way to say “WWW” when reciting a URL.

Upload: To send a file to a network. See also download and crossload.

Virtual: A commonly used adjective that means having all of the properties of x while not necessarily being x. For example, “virtual Friday” in a workplace is the last day of work before a break, that is to say it is like Friday but may or may not actually be Friday. A “virtual reality” is an artificial environment that appears to be its own reality. On a mainframe, a “virtual machine” gives the user all of the properties and “feel” of a separate personal computer.

Virus: An insidious piece of computer code written to damage systems. Viruses can be hidden in executable program files posted online.

Webliography: A listing of source World Wide Web sites.

Webmaster: The person in charge of administrating a World Wide Web site. By convention, the webmaster of Internet domain foo.com can be reached at the email address webmaster@foo.com.

World Wide Web (WWW): A distributed hypertext system invented by Tim Berners-Lee on a NeXT Computer. Currently, one of the most popular services offered on the Internet. Web pages are viewed using browsing software like Netscape Navigator, Sun Microsystems Hot Java, or Microsoft Internet Explorer. See also browser, Hypertext Markup Language, net surfing, and triple-dub.

Worm:

- An insidious and usually illegal computer program that is designed to replicate itself over a network for the purpose of causing harm and/or destruction. While a virus is designed to invade a single computer's hard drive, a worm is designed to invade a network. The most infamous worm was created by Robert Tappan Morris in November 1988; it infiltrated over 6,000 network systems around the globe.- Acronym for “Write Once Read Many”. Used to describe optical disk drives that can only be written once, usually for archival purposes.