What is a server? A server is a computer that provides information to other computers called “clients” on a network. It uses an architecture called the “client–server model.”

Servers can serve various purposes often known as “services.” It can, for instance, share data or resources with multiple clients. It can also perform computations for a client. Note that a single server can serve many clients and a single client can use several servers.

Think of a server as a waiter in a restaurant. He serves multiple customers. While it does not ordinarily happen, other waiters can serve his customers in case he is not available just so no one waits for their orders too long.

Read More about a Server

Servers come in many kinds, depending on their purpose. We will tackle them here along with other pertinent information about the device.

A Brief History of Servers

The word “server” was first used in computing way back in 1969 in reference to RFC 5, which was one of the earliest documents describing the Internet’s predecessor, ARPANET. From then on, server development continued along with the growth of networking.

The 1980s saw the introduction of the client-server model with the production of early server operating systems (OSs) meant for network management like Novell Netware in 1983 and Microsoft Windows NT in 1989. By 1989, Tim Berners-Lee also invented the World Wide Web at CERN.

In 1990, Berners-Lee set up the world’s first web server on a NeXT computer. It had a 2GB disk and 256MHz central processing unit (CPU). By 1993, Microsoft released Windows NT 3.1 Advanced Server, the company’s first commercial server OS based on a new kernel. The rise of the Internet made servers a critical piece of infrastructure, which later on led to the first data centers meant to host websites and email services.

Today, server development continues with advancements in hardware, OSs, and virtualization. Even new server types like application, proxy, and file servers have emerged.

How Does a Server Work?

First off, a device must be configured properly to work as a server. It should be able to listen to requests from clients through a network connection. This functionality can be part of the OS installed on the device, its role in the network, or a combination of the two.

Take Microsoft’s Windows Server OS, for instance. It enables a computer to listen to and respond to client requests. Its designated role, meanwhile, dictates what kinds of client requests the server can respond to.

Now that we have that cleared up, let us tackle how exactly a server works.

How a Server Works

First, a client that requires data or functionality from a server sends a request over the network. The server receives this request and responds with the appropriate information.

Note that in many cases, a server performs additional tasks as part of responding to requests. It can verify the requester’s identity to ensure the client is permitted to access the data or resources requested. It can also format or return the required responses in an expected way.

What Are the Components of a Server?

To work, a server must have essential components that we named below.

  • Hardware: Multiple servers are typically housed in rack mount chassis that contain a power supply, a system board, one or more CPUs, memory, storage, and a control panel up front. They also have various connectors in the back and a network interface.
  • Out-of-band management system: Most server hardware supports out-of-band management through a dedicated network port. This enables low-level management and server monitoring independent of the OS. This system can remotely power the server on or off, install an OS, and monitor device health.
  • OS: An example of this is Windows Server 2025. It acts as the platform that enables applications to run. It gives applications access to the hardware resources they need and enables network connectivity.
  • Application: To do its job, every server needs an application. A database server, for instance, cannot run without a database application.

What Are the Different Types of Servers?

As mentioned earlier, a server’s kind depends on the purpose it serves.

Types of Servers

1. Application Server

An application server hosts an application’s backend that user clients (e.g., frontends, web applications, or locally installed applications) within a network access and use. Note that this type of server does not need to be Internet-connected. It works within a local network, too. It can be accessed by clients with a browser or local frontend or a web server.

2. Catalog Server

A catalog server keeps an index or table of contents of the information available in a large distributed network (e.g., computers, users, files in file servers, and web applications). Directory and name servers are examples of catalog servers. Any computer program meant to find something on a network (e.g., a site user attempting to log in, an email client looking for an email address, or a user looking for a file) can access a catalog server.

3. Communications Server

A communications server maintains the environment necessary to enable communication between two endpoints (e.g., users or devices). It may or may not have a directory of communication endpoints and a presence detection service, depending on the privacy and security parameters of the network it serves. It can be accessed by communication endpoints.

4. Computing Server

A computing server is meant to share vast amounts of computing resources, especially CPU and random-access memory (RAM), throughout a network. It can be accessed by any computer program that needs more CPU power and RAM than a personal computer (PC) has. Note, however, that the client must be network-connected.

5. Database Server

A database server keeps and shares any kind of database throughout a network. Spreadsheets, accounting software, asset management software, or any computer program that consumes well-organized data, especially in large volumes can access it.

6. Fax Server

A fax server shares one or more fax machines across a network, eliminating the hassle of physical access. It can be accessed by any fax sender or recipient.

7. File Server

A file server shares files and folders, storage space to hold files and folders, or both throughout a network. Its intended clients are network-connected computers. Note, though, that even local programs can be its clients.

8. Game Server

A game server lets several computers or gaming devices play multiplayer video games. Any PC or gaming console can access it.

9. Mail Server

A mail server makes email communication possible the same way a post office makes snail mail communication possible. All email senders and recipients can access it.

10. Media Server

A media server shares digital video or audio files over a network through media streaming. Any user-attended PC equipped with a monitor and speaker can access it.

11. Print Server

A print server shares one or more printers among network-connected devices, eliminating the hassle of physical access. All devices in need of printing something can access it.

12. Proxy Server

A proxy server acts as an intermediary between a client and a server by accepting incoming traffic from the client and sending it to the server. It is useful for content control and filtering, improving traffic performance, preventing unauthorized network access, or just routing traffic over a large and complex network. Any network-connected computer can access it.

13. Sound Server

A sound server lets computer programs play and record sound individually or cooperatively. It can be accessed by all the programs in computer and network clients.

14. Virtual Server

A virtual server shares hardware and software resources with other virtual servers. It only exists as defined within specialized software called “hypervisors,” which present virtual hardware to the server as if it was real physical hardware. Note that server virtualization enables better infrastructure efficiency. Any network-connected computer can access a virtual server.

15. Web Server

A web server hosts web pages. It is what makes the Internet work. Note that every website can have one or more web servers and that each web server can host many websites. Any computer with a web browser can access a web server.

Does a Server Need Protection against Threats?

Given that a server provides resources to several clients and can store tons of data for an entire company, it definitely needs protection against threats. Note, too, that Gartner predicted that by the end of 2025, 45% of organizations worldwide will suffer from software supply chain attacks. And guess what? These attacks target servers. So, how can companies protect their servers? We listed some ways below.

Employ Strong Access and Authentication Measures

  • Require the use of strong passwords that are regularly replaced.
  • Implement multifactor authentication (MFA) for an additional layer of security.
  • Limit root and superuser access to only essential personnel.
  • Configure firewalls and access controls to block unauthorized access.

Maintain and Update Systems Regularly

  • Keep all systems and software updated with the latest security patches.
  • Disable unnecessary services and applications.
  • Perform regular security audits and vulnerability assessments.

Protect Data

  • Encrypt both data at rest and in transit to protect sensitive information even if a breach occurs.
  • Create and test regular backups of critical data and server configurations following the 3-2-1 backup rule.
  • Use secure file transfer methods like Secure File Transfer Protocol (SFTP) or File Transfer Protocol Secure (FTPS) when transmitting or moving data.

Constantly Monitor for and Respond Fast to Threats

  • Monitor server logs for suspicious activity.
  • Deploy intrusion detection and prevention systems (IDPSs).
  • Develop and maintain a disaster recovery plan.

Reduce Human Error

  • Train employees to be security-aware.
  • Establish and enforce clear cybersecurity policies.

What Else Can You Do?

  • Secure your physical environment by restricting access to server hardware.
  • Use Secure Sockets Layer (SSL)/Transport Layer Security (TLS) certificates to encrypt connections and protect data transmitted over the Internet.
  • Consider using a killswitch for critical servers.

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You learned the answer to “What is a server?” here. We hope you also realized that a server is a must for any organization. It poses necessary risks amid the ever-growing threat landscape. There are, however, many ways to protect it from threats.

Key Takeaways

  • A server is a computer that provides information to other computers called “clients” on a network.
  • How does a server work? First, a client that requires data or functionality from a server sends a request over the network. The server receives this request and responds with the appropriate information.
  • There are many types of servers, including but not limited to application, catalog, communications, computing, and database servers.
  • While a server is vulnerable to attacks, there are tons of ways to protect it. Employing strong access and authentication measures, maintaining and updating systems regularly, and protecting data are just some of them.

Sources

  • https://en.wikipedia.org/wiki/Server_(computing)
  • https://www.solarwinds.com/resources/it-glossary/server
  • https://www.geeksforgeeks.org/computer-networks/what-is-server/
  • https://www.spiceworks.com/tech/tech-general/articles/what-is-a-server/
  • https://developer.mozilla.org/en-US/docs/Glossary/Server