Why you so confused its really simple. Its your 3rd question on the same title.
See, A pointer is a variable whose work is to point on a address inside the memory.
During execution of a program each variable, function is allocated some memory address inside RAM and with pointer you can access to that memory address with the help of pointer and can make changes to the value associated to that memory address if you want.
PM me for personal help. I will be happy to help you out with pointers.