ymmv but generally these days chat refers to text or voice chat. texting esp has risen in popularity to its own thing
chat involving cam would be cam chat
I do all three and would never just use 'chat' if the service included a cam component. for one thing the rate for cam is much higher. double at least. not gonna brush my hair and kick my cats off the bed for a non-cam rate experience
have never encountered a client who didn't comprehend the difference
try out whatever but if you intend to refer to cam chat, use the word 'cam' or 'webcam' in the phrase. bet you'll have better results
also quite lucrative with clients looking for GFE or exploring a fetish through words and don't necessarily want a 'sex show', but want to know they're not having a convo off-cam with an over-filtered insta image or bot
no shade on the gyals who use those, just not generally to older men's taste (the ones who have a lot of money to spend)
by all means, test out whatever. you won't know what works best for you til you try it
just my

worth exactly that