Fundamentally, what exactly is a codec?

Question

I really hope I don't get down-voted for this, but this is something I have wondered for quite a while now.

I have been reading through a series of articles describing what codecs are/what they do, and the difference between them and Containers, but where I become confused is in what a codec is fundamentally.

Is a codec an executable binary/library that handles the compression/decompression of files for a specific program/API? Or is it a form of library for programmers to use in order to handle these containers?

Reading various answers around the web it sounds as though it's almost treated as both, which is a little confusing. I'm hoping someone here can help clarify.

Thanks!

Answer 1

Like many other terms, the term "codec" describes the logical function, not the form or implementation. The same is true of the very similar term "modem" which can refer to a physical device, a piece of software, or any number of things, provided they modulate and demodulate. A "codec" is anything (program, physical object, library, API, specification) that encodes and decodes digital data.