Browse our list of broadcasting terminology. If you would like further advice on any aspect of broadcast management, please get in touch.


The location on the videotape by time code frame number.


Application Programming Interface. A system or application software that provides resources and functions for programmers to create user interface features or provides access to other applications.

Airtime or air time

The scheduled day or period of a broadcast, described by the beginning time; the length of an actual broadcast of a programme or segment.

Aspect Ratio

The ratio of the width of a picture to the height.

As Run Log

A merged and filtered document/file detailing all material that was actually transmitted on a channel or channels by a system over a period of time.


A group of viewers of a programme. Average audience is a number or rating calculated by Nielsen and other research services, based on specific conditions.

Automation System

Computers that drive playout devices.


Advertising supported Video On Demand


A reference signal recorded on the beginning of a videotape for the purpose of aligning the playback of that tape.


The opening or closing credits or an announcement of a forthcoming program or segment, as on a news or interview program; an announcement related to a sponsor or advertiser, perhaps not paid for, such as "this portion of the program is brought to you by ..."


A group of consecutive time periods. Block programming is the scheduling of programs with similar audience appeal. A news block is a segment devoted to news.

Bookend (also Top & Tail)

A bookend commercial is one that has two parts placed at the beginning and end of a break, with other commercial material placed in between.


An interruption or break in the current programme during which commercial and promotional material is shown.

Break bumper

An animation or logo briefly shown after the end of a program or part of a program before the advertising

Break format

Generic templates for placing breaks at particular positions within programmes.


Programme or Programming that is transmitted as part of a linear schedule.

Broadcast day

The period between the sign-on and sign-off of a TV station, i.e. when as far as the tv schedule goes a new day starts and ends. Start of day for TV channels is often 6am. So the broadcast day would be 6:00:00am – 05:59:59am


An on-screen graphic, often a channel logo, usually located in the corner of the screen.


An element that acts as a transition to or from commercial breaks

Buy rate

In pay-per-view TV, the percentage of subscribers that purchase a program.

BXF (Broadcast Exchange Format)

An XML based standard for data exchange in the broadcasting industry.

Cable television (cable tv or catv)

A television distribution system whereby TV signals are transmitted via cable, rather than through the air, to TV sets of subscribers in a community or locality.


A short segment of a program.

Colour bar

A strip of primary colours and black, used for TV testing and for colour standardisation and accuracy.

Conditional Access

A system for controlling subscriber access to DVB signals using decryption and descrambling methods.  It defines the conditions wherein a viewer is granted access to certain programming.  For instance, paying extra each month for a movie channel, or calling up before a big game and charging your account so you can watch it.

Closed Captioning (also see subtitles)

Te Text version of a program's dialogue, overlaid on the screen either at broadcast or at reception for the hearing impaired or for when a speaker is unclear or speaking in a foreign language.

Commercial break

An interruption or break in the current programme during which commercial and promotional material is shown.


Break Components are used to split programme breaks into specific sections or components. These can be used to structure a programme break and define the type of content that can be scheduled.

CPT: Cost per Thousand

The cost of reaching 1000 people of the target audience.


A programming segment of a broadcast schedule, such as morning, afternoon and primetime for television. Dayparting is the scheduling of programs at specific parts of the day, targeted to specific audiences that are predominant during those times.

Dolby Digital

Also Dolby D. The standard for 5.1 channel (surround sound) audio. Six discrete channels are used (Left, Center, Right, Left Rear Surround, Right Rear Surround, and Subwoofer).

Double pumping

Putting out two episodes of a show back-to-back, either to boost ratings in a given slot or to burn off episodes of a cancelled show.

Drop frame time code

A system that keeps the time of a videotape accurate by dropping two numbers every minute to make up for the small error that results from assuming that video runs exactly 30 frames per second (video actually runs 29.97 frames per second). The length of video in real time is the same

DVB: Digital Video Broadcasting

The MPEG-2 based standard of digital transmission and reception. Comes in variants according to the type of broadcast, e.g. DVB-T for terrestrial.

EOM: End of Message

The timecode at which an event finishes on a piece of media. The duration of an event is determined as the EOM of the segment less its SOM (Start of Message).

EPG (Electronic Programme Guide)

Menu-based systems that provide viewers with continuously updated menus displaying broadcast programming or scheduling information for current and upcoming programming.


Broadcasts sent by TV networks to local stations or by a local station to another.


An advertising campaign, that runs for a specific period, such as four weeks.

Flight Dates

The start and end dates of an advertising campaign


One of the many still images which compose the complete moving picture

Frames per second

The number of times the television is refreshed in a second of time. As a rule of thumb, this is the same as the local Alternating Current electricity supply - 60 Hz or 50 Hz.


An acronym for "General-Purpose Interface". This interface is mostly used in broadcast and post production equipment. Some of these external devices do not have the ability to be directly controlled by the editor. In this case the GPI signal is used to synchronously "start" this equipment at the same time.


One or more individuals who live together in an apartment, house, or other dwelling unit, a common unit for classifying population data. A TV household is a dwelling unit with one or more TV sets.

HDTV: High-definition television

Broadcasting using a line standard of 720 or greater.


Collective term for television and video formats of a resolution higher than standard TV. There are various proposals and standards. The most common formats have 1280 x 720 pixels (SMPTE 296M) and 1920 x 1080 pixels (SMPTE 274M).


A station's symbol or logo, often accompanied by music, a jingle or an animation.


The ratings index for each break, these are used to establish the most effective breaks to book commercials into, when selling commercial airtime based on viewer ratings. Index values are based on percentage share of a Target Audience relative to a Target Audience Group


A segment that combines advertising with information, sold as a commercial and available on some cable networks and other broadcast media.


A combination of information and entertainment, such as that provided by some of the cable-television services.


Referring to a division or unit that is part of or within a company organization, as differentiated from a vendor or an outside agency.


An acronym for "Internet Protocol". The network layer protocol for the internet protocol suite.

Letterbox format

The ratio of width to height (the aspect ratio) used in showing a film on TV so that the film has the same relative dimensions as it did when shown in a widescreen movie theater. Films shown on a TV screen generally do not have their original aspect ratio.

Media Management

Managing media means moving and storing digital content assets in a safe way, while managing requests for duplicates.


A short series or sequence of related programs, such as one every night for five consecutive nights rather than one a week over a 13-week or other extended period.


A group of radio or TV stations that broadcast the same programs. The stations can be owned by a headquarters company--the network--that is the source of the programs or can be independent--an affiliate or network affiliate.

Nielsen ratings

Survey of viewers by the AC Nielsen Company to establish the audiences for individual programs and their demographics.


National Television System Committee: An American committee formed to set the line and colour standard for broadcasting. The format consists of 525 scan lines of resolution at 30 fps and is used in the Americas (except Brazil) and in Japan.

OB: Outside Broadcast

A complete event or programme, or a brief news report, produced and fed back live from location by an OB vehicle to the broadcaster.

Opt out

The moment during a network news transmission or other live feed when a local radio or TV station has the option of discontinuing and returning to its own programming.


An acronym for "Phase Alternating Line". It is a composite colour standard used in many parts of the world. The format consists of 625 scan lines of resolution at 25 fps The phase alternation makes the signal less susceptible to distortion and is used in Europe and Australia & New Zealand, also parts of Asia, Africa and South America.


Reception of a scrambled film or sporting event after the payment of a one-off fee for that broadcast, also known as tVOD (transactional video on demand)


The appearance of blank bars on either side of the picture when 4:3 material is shown on a 16:9 widescreen television set.


A one-off episode of a proposed series, usually in extended form, to gauge audience reaction. If successful, the rest of the series is made and the pilot becomes the first episode.


The transmission of radio or TV channels from the broadcaster into broadcast networks that deliver content to the audience.


The promotion of a forthcoming attraction; also called trailer.

Prime time

The time period that has the greatest number of viewers, generally 8 to 11 p.m.


Short for promotion. The preliminary advertisement or announcement of a TV programme, broadcast in day or days leading up to the programme being broadcast.

Promotional spot

A commercial advertising a programme, station, or network.


The size of TV audience expressed as a percentage of the total potential audience.


Regions are areas or territories that have variations in programming. A channel maybe broadcast across several regions, which have periods of a schedule with slightly different content. For Example: Different local news programming or

Roll (also reel)

A reel or spool of tape or film.

Run-of-station (ROS):

An instruction to broadcast a commercial anytime during a station's schedule.

Satellite TV

A television distribution system whereby TV signals are transmitted via satellite to TV sets of subscribers in a community or locality who will also require a satellite dish to receive the signal.


A list of consecutive programs


A period when new TV programs are introduced by networks. In the US this refers to the autumn/fall season of 13 weeks. Mid-season is between the autumn/fall and spring seasons. A full-season show generally contains 24 episodes.

Secondary Event:

Secondary Events allow you to associate items, such as programme bugs, channel logos or programme titles with primary schedule events - programmes, commercials or promotions. These associated secondary events will then be transmitted simultaneously with the primary event.


The location of a program or commercial on a broadcast schedule.

SOM: Start of Message

The timecode at which an event starts on a piece of media. SOM's are held as the first frame that should go to air. This combined with the duration of the event, will determine the End of Message (EOM) timecode.


A broadcast advertiser who pays to have their commercial content inserted between the end-of-programme-part caption and the break-bumper i.e. played at the beginning and/or end of each part of a particular programme. Sponsorships can also run over entire day parts or programming blocks.


A radio or television commercial

Spot advertising

A commercial or commercials run in the middle of or between programs, sold separately from the program (as opposed to sponsors' messages).

Subtitles (see also closed captioning)

Text version of a program's dialogue, overlaid on the screen either at broadcast or at reception for the hearing impaired or for when a speaker is unclear or speaking in a foreign language.


A visual inserted on the screen, which “squeezes” the main content, these are often used to show promotional material during the previous programmes end credits.


A broadcasting facility.


A copy of an original tape, usually made as a backup in case the master is damaged or lost, also called a safety.


Pay television, in which subscribers, or viewers, pay a monthly fee, as for Netflix.

Time code

A digitally encoded signal that is recorded on videotape in the format of hours:minutes:seconds:frames.

Time slot:

A period in a schedule, as a program scheduled 7:30 to 8 p.m.

Top & Tail (see also bookends)

A Top & Tail commercial is one that has two parts placed at the beginning and end of a break, with other commercial material placed in between.

Traffic department

A department that maintains production schedules to keep work "moving" on schedule. The traffic department in a radio or TV station, maintains the daily broadcast log.

tVOD (Pay-per-view, PPV)

Reception of a scrambled film or sporting event after the payment of a one-off fee for that broadcast, also known as pay-per-view

TVR: Television Viewer Ratings

Values that represent the number of people tuned into a particular programme or a particular channel at a particular time. Ratings information is provided by an external agency specialising in the analysis and processing of this kind of information.

These values can be used to sell commercial airtime based on a targets for reaching a number of viewers of particular audience group or demographic.

Ratings values can be:

Actual: This is correct historical data for a particular channel, region and date, achieved during transmission and provided after a day’s programming has aired. These are usually provided by an external agency.
Predicted: This is actual historical data that has been applied to a date in the future for use as predicted information to sell against.
Estimated: This is estimated data that has been provided by an external agency and is based on your programming for a particular channel, region and date


The visual portion of a broadcast or film; a synonym for television; short for videotape and other television terms.

Videocassette recorder (VCR)

A device for recording and playing videotape cassettes on a TV set or monitor.


Magnetic tape for recording sound and picture, recorded and/or played on a videotape machine such as a videocassette recorder (VCR) for showing on a TV set. Unlike films and records, which can be duplicated quickly, videotapes are duplicated individually and mass production takes a longer time.


Video on demand. Where a movie or other programming is selected for viewing at the customer’s convenience rather than played out by a channel at a specific time. There are a number of types of VOD: aVOD, sVOD, tVOD and catch-up


A transmission of an event, either live or recorded, over the Internet. A webcast extends the audience from potential TV and radio news consumers to a targeted audience at their PCs.

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