There are two major operations push and pop. Push is used to enter values into the stack while pop is used take elements from the stack. The stack has a FILO system, i.e. First In Last Out system.
The stack is usually an array and has a limit and if you enter values greater than the limit then you should give an error message as overflow condition and if you try to pop an empty stack you should give an error message as underflow condition.
Please see the video for more details..