Confused about orgasms

So I'm kind of confused about the whole orgasm idea. Yes, i know it feels good and it's indescribable or whatever but I've also hears there's more than one "type".

Like what is 'squirting'? I've heard it so many times but no one can explain to me how to achieve that or why some girls can't do that?

Some say it's a myth and only pornstars are "capable" of it but others say it's real.

So which is it?