For those who are unaware, there is another project [1] that tracks upstream which adds support for various codecs like Zstandard. Many folks (such as myself) opt to install their releases instead.
Sometimes you see a word used a new way and wonder if you've just been wrong all these years.
You'll see codec used in things like text encoding.
To be clear the codec implements the compression (or other encoding) algorithm. So when talking about codec's we mean the implementation. But when talking about the algorithm, we are talking about the standard of encoding the encoder or decoder implements.
No, rare in general.
It's a layman's co-opting, and laymen outnumber specialists in every field.