'Why' and 'When' should audio encoder's/decoder's be used?

Question

I got a lot of questions in my head in addition to what's mentioned in the title. Here's all of them, take your time answering :D

I'm aware that it doesn't alter the quality of the song/track in any way.

So why do you guys use it?

I mean what do you want to do that makes you use an audio encoder/decoder?

It would be grateful if someone would help by explaining what encoder's and decoder's are in the first place!

should a music producer/mixing/mastering engineer worry about it?

AND

If it is something important to know, then

When while producing a track should I use it?

After mastering a song? OR after mixing but before mastering? OR on any audio track placed in any channel?

Sorry if I made it complicated or confusing :( had to clear my doubts.

Thanks loads to everyone who answers!

Answer 1

http://en.wikipedia.org/wiki/Encoder
http://en.wikipedia.org/wiki/Decoder

These are actually Math/CS/EE concepts, because the use of both is to modify information into and from another representation (be it numerical, electrical, even optical), to serve different uses (like file compression, encryption etc.).

For a sound producer the primary use, if not the only use, is to compress, i.e. minimize file size for distribution purposes. E.g. MP3 file encoding.

Different encoders have different properties. They may be "lossy" or "lossless" depending on whether they lose/toss away some information or whether they simply represent it in a more compact form.

All encoding should be performed after the audio is finished, and it should be done only once per file and always starting from the lossless data (e.g. WAV).