Web 服务器：顾名思义，Web 服务器是一种服务器软件，用于存储 Web 内容并使用 HTTP 协议和其他协议来响应通过 WWW 发出的用户请求。它的主要函数是通过对网站内的网页进行存储、处理和交付给用户，来展示网站的内容。
示例：Apache、NGINX、Microsoft Internet Information Services (IIS) 等。
邮件服务器：邮件服务器，类似于邮局，是一个负责接收、路由、发送电子邮件的计算机系统程序。它也称为 MTA(邮件传输代理)并存储传入的邮件以分发给用户并将电子邮件发送到客户端计算机。
示例：Yahoo!、Gmail 接收邮件服务器、Gmail 发送邮件服务器等。
Web 服务器与邮件服务器
|
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). |