Video Technology Glossary

Here are some common terms used in digital video and audio technology that will help you understand the basic jargon. This is a growing list that we hope to update frequently.


A high definition video format with 1080 vertical lines of interlaced (the “i” in 1080i) video, where 540 odd numbered lines are scanned during the first field of video in 1/60th of a second, and the other 540 even lines scanned in the second field. Together, these two fields form a complete frame of video in 1/30th of a second. The resulting image is presented in a 16:9 aspect ratio at 1920 x 1080 resolution. 1080i is used by several television broadcast and cable networks to deliver high definition video.


A high definition video format with 1080 vertical lines of progressive (the “p” in 1080p) video, where all 1080 lines are scanned at once per video frame in 1/30th of a second. Movies for Blu-ray are often scanned and played back at 24 frames per second, as that is the standard for motion picture film cameras. Progressive scanning allows for clearer, shaper images and improves how motion is displayed. The resulting image is presented in a 16:9 aspect ratio at 1920 x 1080 resolution.


Standard definition format with 480 vertical lines of interlaced (the “i” in 480i) video, where 240 odd number lines are scanned during the first field of video in 1/60th of a second, and the other 240 even numbered lines are scanned in the second field. There are two fields per video frame displayed in 1/30th of a second. Used for DVDs, with a resolution of 720 x 480.


Standard definition video where 480 vertical lines of progressive (the “p” in 480p) are scanned at one time to compose a video frame in 1/30th of a second. Progressive scanning allows for clearer, shaper images and improves how motion is displayed. 480p is used extensively in DVD authoring, and is one reason why the resulting 720 x 480 resolution image can be “up-scaled” with high quality on a display designed for 1920 x 1080.


A high definition video format which scans the 720 vertical lines at one time during a video frame in 1/30th of a second. Progressive (the “p” in 720p) scanning allows for clearer, shaper images and improves how motion is displayed. 720p is presented in a 16:9 aspect ratio at 1280 x 720 resolution. Progressive scanning also allows for better “up-scaling” of a 1280 x 720 image to fill a display screen designed for 1920 x 1080. 720p is used by several broadcast and cable networks to deliver high definition video.


A media container format used for many mobile phones.


Advanced Audio Coding. A digital audio compression standard providing very high sound quality at relatively low bit rates.


Advanced Video Coding High Definition. A format using MPEG-4 AVC/H.264 compression originally made for consumer HD camcorders. AVCHD can be played on media players in computers, or burned onto DVD recordable media and played back on Blu-ray machines at 1920 x 1080 resolution.


Developed by Microsoft for use in their Windows PC architecture, the formal name for the AVI  is Audio Video Interleave (Interleave because the video and audio are bound together in chunks). AVI is not a CODEC itself. It is a container or a “wrapper” which allows different CODECs to be placed inside for playback.  Click here to read more about the history of AVI and AVI players.


The speed and amount of data that can be transferred in a given period of time. Higher bit rates mean higher quality media can be streamed or played back. Overall bandwidth depends upon the processing speed of your computer, along with the network or Internet connection.


Is a number of bits per second that can be transported or processed. Audio and highly compressed video runs in the Kilobits per second range. Other video compressed through different codecs may play at Megabits per second rates, usually because they are playing back higher quality content. Newer codecs, such as H.264, are more sophisticated and very efficient. They can operate at lower bits rates, but still deliver excellent quality video and audio.


A high definition video standard of 1080p at 1920 x 1080 resolution, primarily used for playing back Hollywood movies. The Blu-ray specification currently allows for very high bit rates, up to 40 Megabits per second. Blu-ray discs must be encoded in H.264, MPEG-2 or the VC-1 codec.


General term meaning recording data to special CD, DVD or Blu-ray media. It’s called ‘burning’ because a laser melts a special chemical layer in the recordable media to create pits and bumps, which reflect light different to mimic digital data. Commercially produced movies are created through a different way called replication, where a mechanical stamping process makes the pits and bumps.


An amount of memory set aside to help improve media playback performance by allocating space to either RAM or hard disk drive.


Constant Bit Rate. A recording preference where, regardless of its quality or complexity, the content will be recorded at the same bit rate from beginning to end. The opposite of Variable Bit Rate (VBR), where the bit rate changes up and down according to the amount of data required by the compression algorithm.


Compact Disc. A media format used to store and playback music and data. Typical capacity of 700 Megabytes (MB.)


A term usually in reference to a section of or sometimes even an entire video program.


Compression-Decompression. Highly specialized algorithms that analyze content of the media, using a variety of rules to remove or exclude redundant information within the video or audio material to greatly reduce the size for storage, transmission and playback efficiency. There are many CODECs, each designed for specific purposes. Virtually all digital media used in consumer applications are compressed.


A type of file, also called a wrapper or envelope, which can hold different CODECs according to the design of the container. AVI, FLV, MKV, MP4, QuickTime, RM and WMV are examples of containers used for multimedia players.


A software program of changing one media format to another for use in different devices. Often used to take a media format that plays on a computer and transfer it to one that will play on a smart phone, tablet or other mobile device.


A computer program which allows you to save a video running on the web to your local computer, where it can be stored in your library for playback later, or perhaps converted to display on a mobile device.

DVD Digital Video Disc

Similar to a CD in physical structure, but can hold seven times the data capacity. Primarily designed for recording movies in the MPEG-2 format and Dolby Digital Surround sound. DVD-R/RW media can record video or data.


Often used in the same context as compression. Taking one media format and making it into another. e.g., used to change original content from a Non-Linear Editing system (NLE) to a new format in a smaller size to save space and play on a different type of system such as DVD or Blu-ray. Also referred to as Transcoding.

File Format

A general term that is often used interchangeably to mean the container format or (incorrectly) a codec itself. Common formats include: AVI, MP4, WMV, 3GP, QuickTime, SWF, MPEG, M4V, RM, DVD, DVR-MS, MKV and FLV.

GPU Acceleration

Ability of video player software to take advantage of the Graphics Processing Unit hardware in a computer, mobile device or game machine to make the decoding and display of digital video faster and more reliable


A codec which is part of the MPEG-4 standard for high definition video. H.264 is very efficient and enables delivering very high quality at relatively low bit rates. This is especially useful for Internet content and use on mobile devices. It is also one of the mandated standards for Blu-ray, being capable of encoding video at high bit rates.


Hyper Text Markup Language, version 5. An increasingly popular language for use on the Internet. One advantage is the provision for embedding video and audio directly in HTML5. This makes delivering video and audio more efficient directly through web browsers.


Location where your collection of audio and video media clips are stored. Can be customized according to how you want to categorize content, and used as part of the interface to provide access to other features.


A type of encoding that, although compression techniques are used, the resulting product can be played back without loss of data.


Encoding that permanently removes data during compression in a way that not only makes the final product much smaller, but still offers very high quality.


A digital audio encoding format, predominant in portable audio devices.


A popular container format, which can carry the H.264 codec for very high quality video at low bitrates. Click here to find out more about MP4s and how to choose an MP4 player. You can also read about how to find free MP4 videos.


Moving Pictures Experts Group – 2. A very popular encoding format for both standard definition and even high definition. MPEG-2 is the standard for DVDs, and is used extensively by digital television for distribution over broadcast, cable and satellite services. Although not used as much as H.264 and VC-1 because MPEG-2 is not as efficient, it is one of the three standards mandated for Blu-ray.


The software that recognizes formats, decodes the compression algorithm and displays your media content on your computer or mobile device. Not all players can properly interpret all formats or codecs. Click here to read more about finding the best media player.


A sequence of media clips which you can set to playback in a particular order.


Special setting to adjust the user interface, determine technical playback parameters, make changes to your Internet connection, etc.


For digital video, measured by the resolvable detail given the number of the vertical and horizontal pixels on a display device. Other factors such as spatial (still images), temporal (moving images or objects) and the perceived resolution of the viewer makes this more than a numbers game.


Continuous transmission of content that can’t be paused or rewound. Essentially like a live broadcast.


Used interchangeably with encode and conversion. Typically changing one media format to another. Usually involves compression to make the final product into a smaller delivery package.


A simplified version of editing, that is confined to changing the in and out points of a clip. Does not include the ability to merge clips together in a sequence.


Variable Bit Rate. An economical way to compress and encode video source material based on the algorithms’ ability to detect changes in the amount of data most appropriate for a particular scene. For video, this saves space by using fewer bits for simple content, and more for complex material that contains lots of changing detail or motion.


A video compression format originally developed by Microsoft for the now defunct HD DVD standard, which was dropped in favor of Blu-ray. VC-1 is one of the three mandated formats for use on Blu-ray. It is an efficient codec, which can deliver very high quality.