Some terms used in the area of Audio/Video and there meaning.
The ratio of width to height of a video
The number of bits of data to be played per second.
A part of the program which understands a type of video or audio.
To understand and play a file, VideoLAN needs to decode it. It does this with a decoder.
An elementry stream, a single channel of audio, video or subtitles (without a container).
The number of frames of video displayed (or encoded to be displayed) per second.
Displaying an image on top of the video
Transcoding is changing the format of a file.