What Size Jersey Should I Buy Nba - MySport

If the size of the int is that important one can use int16_t, int32_t and int64_t (need the iostream include for that if I remember correctly). What's nice about this that int64_t should not have issues on a 32bit system (this will impact the performance though). In several C++ examples I see a use of the type size_t where I would have used a simple int.

What's the difference, and why size_t should be better?