Long or short integer..what that mean ? Is it about the storage in memory ?

Answer 1

Yes, it's about the place it takes in the memory.
The short will take less space than int and long will take a little bit more.

Answer 2

short and long takes a certain place in memory.
The size of the int depends on the machine. For example : on a 16bits machine, int and short will have the same size (2 octets) ; on a 32bits machine, int and long will have the same size (4 octets)

Answer 3

if we didn't declare the size of memory..just an integer..the memory will be just for the little numbers or all size ?