The document introduces the stack as a linear data structure that operates on a last in, first out (LIFO) basis, allowing insertion and deletion only at the top through push and pop operations. It explains essential terms related to stack operations, including overflow, underflow, and peek. The stack is characterized as a dynamic data structure that can grow or shrink in size based on the push and pop activities.

1. TOPIC : INTRODUCTION OF STACK

2. Stack
• Stack is a linear Data Structure implemented in LIFO(Last In First
Out) manner where insertion and deletion of element are
performed only at one end i.e. top of the stack.
• It is a collection of data items in which data items are inserted and
deleted from the top of stack.
• The removal of element from stack is called POP operation.
• The insertion of new element at the top of the stack is called PUSH
operation.
• Stack is also called Dynamic Data Structure because the stack
implemented by list can grow(i.e. increase number of elements)
and shrink(i.e. decrease the number of elements)

3. Representation of Stack
with Push and Pop operations

4. Other Stack Terms
1- Overflow:- It refers to the situation when one tries to
push(insert) an item in stack that is already full. This
situation occurs when the size of stack is fixed and can
not grow or there is no memory left to accommodate
new item.
2- Underflow:- It refers to the situation when one tries to
pop(delete) an item from the empty stack.
3- Peek:- It refers to inspecting or get the value from the top
of the stack i.e. Peek means to know the topmost
element of stack

5. Illustrating Overflow and Underflow Condition

6. Illustrating Overflow and Underflow Condition