This is a general overview of the different and audio video standards for computers, movies, Blu-Ray players, and so on. It will not delve into how each standard works.
The first thing you must know is that the real world is not digital, but analog. A synonym for analog is infinite and for digital is finite. What this means is that we must convert the analog real world to a format our electronics can process. This is where a codec comes into play. Codec is short for coder/decoder. A codec is an algorithm that converts the analog real world into groups of 1’s and 0’s. Newer codecs do a better job of this conversion and thus have a smaller file size or are closer to the real world equivalent.
The second thing you must know is the difference between lossless and lossy. Like the names suggest, lossless does not discard any data in the algorithm. The quality is therefore higher but the file size is higher too. Lossy algorithms discard data to achieve a smaller file size. Ideally a lossy algorithm would appear the same as a lossless one.
Techs-on-Call Computer Repair Notes 