As above, the 'races' are basically all humanoid and yes, that just means 'human, but different'. It is also canon that the various races can interbreed, but that children born from such mixed-race unions are very rare (Hilda in the Heavensward expansion being a particularly well-known hyur/elezen example).

Also, a possible origin of the races and the implications of how human-like they are is kind of touched on in the most recent Shadowbringers expansion, but that is a big spoiler so I won't say anything more.