When people talk about "cumming," sometimes that refers to having an orgasm, and sometimes it refers to ejaculation. "Squirting" is a colloquial term for ejaculation when done by someone with a vulva (also called "female ejaculation" although not everyone with a vulva is female). We have some information about that here: Squirt: On Ejaculation
So, the difference is going to depend on what someone means by "cumming;" ejaculation can happen with orgasm, but doesn't always, so it could be that someone's referring to two different things that could
happen around the same time or that they're referring to the same thing.