Difference between Web Server and Mail Server

Web Server: Web Server, as the name suggests, is a server software where web content is stored and uses HTTP protocol and other protocols to respond to user requests that is being made over WWW. Its main function is to display the content of the website through storing, processing, and delivering webpages within the website to users.  

Example: Apache, NGINX, Microsoft Internet Information Services (IIS), etc. 

Mail Server: Mail Server, similar to the post office, is a computer system program responsible for receiving, routing, delivering e-mail. It is also known as MTA (Mail Transfer Agent) and store incoming mail for distribution to users and deliver e-mail to client computers.  

Example: Yahoo!, Gmail incoming mail server, Gmail outgoing mail server, etc.  

Web Server vs Mail Server

Web Server	Mail Server
Web servers basically handle, manage, and run one or more websites.	Mail Servers basically handle, manage, and delivers e-mail over the internet.
It delivers content for website to user or visitor that wants it same as a web browser.	It delivers and receive email messages same as post office.
Its main objective is to display website content through storing, processing and delivering web pages to users or visitors.	Its main objective is to act as virtual post office and make communication possible between various employees of organization or business or company.
It is important for users to view website because without web server, users won’t be able to have access to content of websites at all.	It is important for users to store their documents, files and videos in cloud storage.
Types of web servers include Apache HTTP server, Jigsaw server, LiteSpeed Web server, etc.	Types of mail server include POP3 mail server, IMAP mail server, SMTP mail server, etc.
Its main function is to host website and distribute web pages as they are requisitioned.	Its supports e-communication, content and file sharing, etc.
It follows a network protocol known as HTTP (Hyper Text Transfer Protocol).	It follows SMTP (Simple Mail Transfer Protocol).

Source: geeksforgeeks.org