Glossary of Media Terms

"D" Counties – The classification of counties based on Census household counts and metropolitan proximity. "D" counties are all counties not classified as A,B or C counties. They are considered very rural. The combined counties contain 15% of United States households.

Data – Facts or figures from which conclusions can be drawn. A plural noun.

Daypart – The time segments that divide a radio or TV day for ad scheduling purposes. These segments generally reflect a television station’s programming patterns. The most common dayparts are: prime time, daytime, late night, early morning, total day, sign-on/sign-off, prime access and fringe. There is no universal agreement, however, about the exact times for all these dayparts, and for this reason, Nielsen Media Research reports the data by time of day.

Daytime – See, Daypart.

DBS – See Direct Broadcast Satellite.

Decoder – An electronic device used for converting a scrambled TV signal into a viewable picture.

Dedicated Channel – Usually a cable television channel devoted to a single source for its programming, e.g., a public access channel or a program schedule channel.

Delayed Broadcast (DB) – The broadcast by a local station of a network program at a time later than its regularly scheduled network time.

Demographics – Audience breakdown based on various characteristics such as age, sex, income, education, etc. (Abbr: Demos)

Designated Market Area (DMA) – A term used by Nielsen Media Research to identify an exclusive geographic area of counties in which the home market television stations hold a dominance of total hours viewed. There are 210 DMA's in the U.S.

Diary – A form on which a sample of respondents is asked to keep a written record of TV viewing or radio listening.

Digital certificate - An electronic method of verifying the identity of a person or corporation; it is essentially a digital signature. The certificate is designed to prevent fraud or impersonation in Internet-related transactions.

Digital Signals – Information transmitted in discrete pulses rather than as continuous signals. Data is represented by a specific sequence of off-on electrical pulses. (See also, Analog)

Direct Broadcast Satellite (DBS) – A satellite service whose signal is delivered directly to a viewer’s home via the use of the viewer’s own earth station dish. DBS is different from traditional satellite systems because they use a smaller more versatile dish to receive programming at higher frequencies (KU-Band).

Distant Signal – A television broadcast station signal not defined by the FCC as "local" to the community in which a cable system is located.

Domain Name – The part of an Internet URL (Universal Resource Locator) selected and registered by an individual, business or organization to represent their web presence. It consists of at least two parts that are separated by "dots." The last part or suffix indicates the type of site, such as ".edu" for schools, ".gov" for government, and ".com" for commercial business.

Downlink – To receive from a satellite; also, the dish used for reception.

DSL – Digital Subscriber Line. These lines carry data at high speeds over standard copper telephone wires. With DSL, data can be delivered at a rate of 1.5 megabits per second (or around 30 times faster than through a 56K modem). In addition, DSL users can receive voice and data simultaneously, so they can use the Internet and make phone calls on the same line at the same time.

DMA – See Designated Market Area.

Duopoly Rule (Local TV Multiple Ownership Rule) - An FCC rule under which common ownership of 2 TV stations will be permitted without regard to the stations' Grade B contours if the stations are in separate Nielsen Designated Market Areas ("DMA"). Also, common ownership of 2 TV stations in the same DMA is allowed if their Grade B contours do not overlap or if 8 independently owned, full-power and operational TV stations will remain post-merger and one of the stations is not among the top four-ranked stations in the market.