Difference between /rest and /api/v2

rest

#1

Salutations,
Most of the references I for sample URLs are [SERVER]/api/v2/[SERVICE]… but looking at some older documentation, I found that this endpoint also works [SERVER]/rest/[SERVICE]. Also, changing the version number doesn’t seem to matter - /api/v2 or /api/q5333412 seem to work as well, but just /api/ does not. Are their other endpoints built-in? Are there differences between them?

Thanks!
Josiah