GENERAL KNOWLEDGE

Detailed explanation-1: -The stack in digital computers is essentially a memory unit with an address register that can count only (after an initial value is loaded into it). The register that holds the address for the stack is called a stack pointer (SP) because its value always points at the top item in the stack.

Detailed explanation-2: -They can be used to maintain a list of operations for an ‘undo’ function in a piece of software, where the most recent operation is the first to be undone. Stacks are also used to facilitate recursive subroutines where the state of each call is stored in a stack frame and placed on a stack.

Detailed explanation-3: -A typical digital computer system has four basic functional elements: (1) input-output equipment, (2) main memory, (3) control unit, and (4) arithmetic-logic unit. Any of a number of devices is used to enter data and program instructions into a computer and to gain access to the results of the processing operation.