# What is the Difference Between Stack and Linked List

The main difference between Stack and Linked List is that a Stack works according to the FIFO mechanism while a Linked List works by storing the data and the addresses of other nodes to refer to each other.

A data structure is a way of storing data elements in computer memory. Data structures are useful as they help to access data efficiently. Linear and nonlinear data structures are two types of data structures. Linear data structures store data in a sequential manner. In other words, these data structure store data one after the other. Stack and Linked List are two such linear data structures.

### Key Areas Covered

1. What is Stack
– Definition, Functionality
2. What is Linked List
– Definition, Functionality
3. Difference Between Stack and Linked List
– Comparison of Key Differences

### Key Terms

Circular Linked List, Double Linked List, Linear Data Structures, Linked List, Single Linked List, Stack

## What is Stack

A stack is a data structure similar to real-world stacks such as a pile of plates, books or a deck of cards. It is only possible to read a single element at a given time.  It works according to the “First In Last Out” (FIFO) mechanism. In this mechanism, the first inserted element is the last element to remove from the stack. The last inserted element is the first element to remove from the stack. It is also called Last In First Out (LIFO).

Stack performs various operations. The push operation allows storing an element at the top of the stack while the pop operation helps to remove the topmost element from the stack. Furthermore, the peek operation helps to read the top element without eliminating it from the stack. If there are no elements, the stack is empty. Moroever, it is not possible to insert elements when the stack is full.

## What is Linked List

Linked List is a data structure with a set of nodes arranged in a sequential manner.

There are three types of linked lists.

Single linked list – A node in this type of list stores the data and the address of the next node. It forms a structure similar to a chain. Inserting, deleting and traversing through the elements are some operations that can be performed on a single linked list.

Double linked list (Doubly linked list) – A node in this type of list stores data and two addresses. These are the address of the next node and the address of the previous node. The two references allow going forward and backwards through the elements in the list. Similar to a single linked list, the programmer can perform operations such as insertion, deletion and traverse on a double linked list.

Circular linked list – In these lists, the last node stores the address of the first node. Thus, it forms a circular chain structure.

Linked lists are dynamic. Therefore, it is not necessary to allocate memory initially. It is possible to allocate memory as required. On the other hand, it is not possible to access a specific element at once. One has to go through each node to one after the other to access a particular element.

## Difference Between Stack and Linked List

### Definition

A stack is an abstract data type that serves as a collection of elements with two principal operations which are push and pop. In contrast, a linked list is a linear collection of data elements whose order is not given by their location in memory. Thus, this is the main difference between stack and linked list.

### Operations

Push, pop and peek are the main operations performed on a stack while insert, delete and traversing are the main operations performed on a linked list.

### Access elements

In a stack, the topmost element can be read. On the other hand,  in a linked list, if the programmer wants to access a specific element, it is necessary to traverse each element from the beginning.

### Functionality

A stack works according to the FIFO mechanism whereas, in a linked list, the elements connect to each other by references. Hence, this is another difference between stack and linked list.

### Complexity

Moreover, a stack is simpler than a linked list.

### Conclusion

Stack and Linked List are two linear data structure. A programmer can implement them using any programming language. The main difference between Stack and Linked List is that a Stack works according to the FIFO mechanism while a Linked List works by storing the data and the addresses of other nodes to refer to each other.

##### References:

1.“Introduction to Linked Lists.” Studytonight via Commons Wikimedia.
2.“DS Stack – Javatpoint.” Www.javatpoint.com via Commons Wikimedia.

##### Image Courtesy:

1.”Source: [1]” By The original uploader was R. Koot at English Wikipedia. – Transferred from en.wikipedia to Commons (CC BY-SA 3.0) via Commons Wikimedia
2. “Singly Linked List” By Singly_linked_list_insert_after.png: Derrick Coetzeederivative work: Pluke (talk) – Singly_linked_list_insert_after.png (Public Domain) via Commons Wikimedia

### About the Author: Lithmee

Lithmee holds a Bachelor of Science degree in Computer Systems Engineering and is reading for her Master’s degree in Computer Science. She is passionate about sharing her knowldge in the areas of programming, data science, and computer systems.