This document describes a Java program to implement a stack data structure using both an array and linked list. It defines a Stack interface and ArrayStack and LinkedListStack classes that implement the stack. The ArrayStack uses an array to store elements while LinkedListStack uses linked list nodes. Methods like push(), pop(), top(), and topAndPop() are implemented to add/remove elements from the stack. Exception handling is included for empty stack cases. Sample code tests inserting characters and numbers into both stack implementations.