Call Stack

           Each time a method is invoked,the system creates an activation records that stores parameter and variables for the method and places the activation record in an area of memory known as a call stack.A call stack is also known as an execution stack,runtime,stack or machine stack and iti is often shortened to just -the stack-.When a method calls another method,the caller's activation record is kept intact,and a new activation record is created for the new method called.When a method finishes its work and returns to its caller,its activation record is removed from the call stack.
            A call stack stores the activation records in a last-in,first-out fashion:The activation record for the method that is invoked last is removed first from the stack.