Introduction to Computer Networks

Servers

A server stores data to be used by other computers on a network. A server could be a specialized machine, or it can be a normal PC running server software. The server stores data and responds to requests for data or files, such as web pages.

Types of Server

There are many different types of servers. Some popular examples follow.

Web Servers

Web servers host websites and generally handle requests for static information such as HTML pages or images. They are used to manage the website on the server and often include FTP software, which can easily host and share large files. The Apache web server is a popular type of open-source web server software.

Application Servers

Many websites are classed as web applications, which contain programming and scripts that are more complex than a static HTML page. For example, many websites use databases held in MySQL or NoSQL databases, which will be accessed via the application server. The application server is generally used to organize and run the web application. A client sends requests to the web server, which sends requests to the application server.

Network Attached Storage (NAS)

This is a server dedicated to storing and sharing files. It is useful for storing large files, such as music and video, but it is not used for storing websites.

Print Servers

These make it easy for various devices to connect to a printer. This removes the need for devices to install the printer driver software or connect to the printer using cables.

Mail Server

These store email messages. Your browser makes requests to mail servers to retrieve the messages.

Network Types

LAN

A LAN (local area network) is a network of computers within the same building, such as a school, home, or business. A LAN is not necessarily connected to the internet.

WAN

A WAN (wide area network) is created when LANs are connected. This requires media such as broadband cables and can connect up organizations based in different geographical places. The internet is a WAN.

VPN

A VPN (virtual private network) is usually hosted securely on another network, such as the internet, to provide connectivity. VPNs are often used when working on secure information held by a company or school.

WPAN

A WPAN (wireless personal area network) allows an individual to connect devices (such as a smartphone) to a desktop machine or to form a Bluetooth connection with devices in a car. A wired personal network is called a PAN (personal area network).