Things the client knows about entities in standard Quake from the server:
The model name
--- frame
--- colormap
--- skin number
--- effects (EF_BRIGHTFIELD, etc.)
--- origin (with previous update stored)
--- angles (with previous update stored)
And technically the baseline.
[A mildly extended protocol like FitzQuake 666 provides a few other pieces of info like alpha and such]
Client entities doesn't cover particles or sounds.