Hi
(Acronym)Hit It Term people in retail use to describe members of the opposite sex (or same) based on hitabliity of said person. It is used as a type of code so customer have no idea they are the object of sexual fantasy etc.
Hot customer walks in...
Danny: (to colleauge) Hi?
Pedro: Hi!

There are also other variations.

e.g. Hi?
if the other person doesn't quite agree or are ambivilent they can reply "hey" which is like meh

Lastly; 
Danny: Hi?
Pedro: Hello!

Hello is an emphasise of "Hell No, nigger!"