'Later' of 'See you later'
In short, "see you later" is more specific than only saying "see you."
Generally, adding "later" will make it sound like you do want to meet again, but are unsure when that will happen.
E.g. "Will I see you at the meeting tomorrow? No? Okay, I'll see you later, then."
I could not say this, however, if I was leaving the office and expecting to see my coworker the next day. I would have to say "See you tomorrow," but I would likely abbreviate this and instead say "See you."