> Hi,
>
> Is there any difference in meaning between hi, hello and hi there? Are
> they the same and can we use them in place of each other?
"Hello" is more formal - "hi" and "hi there" are very informal.
> By the way
> what is the meaning of "there" in hi there?
It doesn't really have any meaning. It just simply adds a further touch
of informality.
Regards, Einde O'Callaghan