Question - What operations can be performed on a stack? 
          
        
        Answer - 
        
Mainly the following operations are performed on a stack:
- Push operation: To add an item to the stack. If the stack is complete, then it is in an overflow condition.
 - Pop operation: It is used to remove an item from the stack. If it's an empty stack, then it is in underflow condition.
 - isEmpty operation: If the stack is empty returns true, else false.
 - Peek or Top operation: This returns the top element of the stack.