Advanced Audio Coding:

AAC is a lossy compression format for digital audio. It is designed to succeed MP3 format, and it usually provides better audio quality than MP3.

aspect ratio:

The ratio of width to height for an image like a video frame. Two common aspect ratios are 4:3 (sometimes called “full screen”) and 16:9 (sometimes called “wide screen”).

codec:

(COmpression/DECompression) A format to compress and decompress data. Common video codecs are H.264, FLV1, Sorensen, and VP6. Common audio codecs are AAC, WAV, and MP3.

container format:

A standard defining a multi-part digital video file. Parts held in the file are audio, video, and metadata like subtitles or captions. Common container formats are AVI, FLV, MOV, and MP4.

data rate:

The amount of data that can be moved in a set time period; the rate for streamed media is usually expressed as kilobits per second (kbps). A higher data rate usually makes a higher quality video.

frame rate:

The number of video frames (AKA images) that can be displayed in a time period, usually seconds, and written as frames per second (fps). Standard video is 30 fps, and 24 fps video is acceptable.

frame size:

(AKA resolution) The width and height of a video frame expressed in picture elements or pixels. Two common frame sizes are 640 x 480 and 320 x 240.

H.264

H.264/MPEG-4 Part 10 or AVC (Advanced Video Coding) is a compressed video format for making and sharing high-definition video. It was designed to display good video at low bit rates, and it is commonly used for streaming video on the Internet.

kilobit:

One thousand binary digits or bits. It is often used as a measure of the data rate over a digital network.

MP4

MP4 or MPEG-4 Part 14 is a file format for multimedia. It can store audio and video streams as well as still images and subtitles. A hint track can also be included to provide streaming information for distribution over the Internet.