Servers Are The Heart and Lungs of the Internet

The internet wouldn't exist without servers

Illuminated server room panel
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A server is a computer designed to process requests and deliver data to another computer over the internet or a local network.

The word "server" is understood by most to mean a web server where web pages can be accessed over the internet through a client like a web browser. However, there are several kinds of servers and even local ones like file servers that store data within an intranet network.

Although any computer running special software can function as a server, the most typical use of the word references the very large, high-powered machines that function as the pumps pushing and pulling data from the internet.

Most computer networks support one or more servers that handle specialized tasks. As a rule, the larger the network - in terms of clients that connect to it or the amount of data that it moves - the more likely it is that several servers play a role, each dedicated to a specific purpose.

Strictly speaking, the "server" is the software that handles a certain task. However, the powerful hardware that supports this software is also usually called a server because server software coordinating a network of hundreds or thousands of clients requires hardware much more robust than what you'd buy for ordinary consumer use.

Common Types of Servers

While some are dedicated servers where the server operates one function only, some implementations might use one server for multiple purposes.

A large, general-purpose network supporting a medium-sized company will likely deploy several different types of servers:

Web Servers

Web servers show pages and run apps through web browsers.

The server your browser is connected to right now is a web server that's delivering this page, any images you might see, etc. The client program, in this case, is most likely a browser like Internet Explorer, Chrome, Firefox, Opera, Safari, etc.

Web servers are used for all sorts of things in addition to delivering simple text and images, like for uploading and backing up files online through a cloud storage service or online backup services.

Email Servers

Email servers facilitate the sending and receiving of email messages.

If you have an email client on your computer, the software is connecting to an IMAP or POP email server to download your messages to your computer, and an SMTP server to send messages back through the email server.

FTP Server

FTP servers support the moving of files through File Transfer Protocol tools.

FTP servers are accessible remotely via FTP client programs.

Identity Server

Identity servers support logins and security roles for authorized users.

Hundreds of different types of specialized server types support computer networks. Apart from the common corporate types, home users often interface with online game servers, chat servers, audio streaming services, etc.

Network Server Types

Many networks on the internet employ a client-server networking model integrating websites and communication services.

An alternative model called peer-to-peer networking allows all devices on a network to function as either a server or client on an as-needed basis. Peer networks offer a greater degree of privacy because communication between computers is more targeted, but most implementations of peer-to-peer networking aren't robust enough to support very large traffic spikes.

Server Clusters

The word cluster is used broadly in computer networking to refer to implementations of shared computing resources. Typically, a cluster integrates the resources of two or more computing devices that could otherwise function separately for some common purpose (often a workstation or server devices).

A web server farm is a collection of networked web servers, each with access to content on the same site that functions as a cluster, conceptually. However, purists debate the technical classification of a server farm as a cluster, depending on the details of the hardware and software configuration.

Servers at Home

Because servers are just software, people can run servers at home, accessible only to devices attached to their home network. For example, some network-aware hard drives use the Network Attached Storage server protocol to allow different PCs on the home network to access a shared set of files.

The popular Plex media server helps users consume digital media on TVs and entertainment devices regardless of whether the media files are on the cloud or on a local PC.

More Information on Servers

Since uptime is of utmost importance for most servers, they are normally never shut down but instead run 24/7.

However, servers sometimes go down intentionally for scheduled maintenance, which is why some websites and services notify their users of "scheduled downtime" or "scheduled maintenance." Servers might also go down unintentionally during something like a DDoS attack.