introduction of Stack

Introduction of Stack

• A data structure that implements this concept is called a stack.
• A stack is a collection of data items that can be accessed at only one end, called top. 
• Items can be inserted and deleted in a stack only at the top. 
• The last item inserted in a stack is the first one to be deleted.
• Therefore, a stack is called a Last-In-First-Out (LIFO) data structure.

There are two basic operations that are performed on stacks: 

• PUSH
• POP

PUSH: It is the process of inserting a new element on the top of a stack.

POP: It is the process of deleting an element from the top of a stack.