You can chroma key in Photoshop two ways; a good way and a bad way.
The good way is to use the Blend If command and do it by a channel (I’d recommend a or b channels, if you have a green or blue background, rather than the B or G channels). The bad way is laborious and inefficient, but is the one everyone recommends on the internet (making a selection).
There is one catch, though; buying After Effects or a similar programme will give you “feathering” for chroma keying. If PS had this one simple feature in the Blend If, then it would be *better* at chroma key than anything else, because you could use any channel you wanted.
Anyway, to answer your question, you use Blend If. The quality will be OK, but not be “pro” level because there is no feathering. (Adobe includes feathering everywhere, but there).
cheers,
Chris