What is a Computer Server?

We all use computers — some of us are on our laptops all day, every day. But how do our personal or work computers connect to the internet, share files, send emails, and complete other tasks? That’s the role of servers. 

What is a computer server?

A server is a system — either hardware or software — that serves resources, data, services, or programs to computers (called clients) over a network.

Servers are the heart of computer operations: if you’re a large enough company, you probably run some of your own data centers: rooms full of servers that power your business.

(Read about data center optimization & data center security.)

Why do you need a server?

Modern businesses need a centralized data storage location. Any computer can technically be a server if it’s set up correctly. But if you’re running a business with multiple employees — all using computers — then you need a designated server that can handle your IT needs. 

Some important reasons for servers include maintaining data backups, hosting domain-specific email, enabling remote access via virtual private networks (VPNs), and controlling permissions. 

How servers work

Servers store and manage massive amounts of data and they make that data accessible over internal networks or the Internet. (We’ll see the various ways servers do this, later on.)

It may seem complicated, but the functionality of computer servers is surprisingly straightforward.

Simply put, a server is a computer that communicates with other computers. When one of those other computers — called “clients” — requests something, like a webpage, file, or service, a server fulfills the request. In other words, they serve! 

Server components

A server is not a standalone piece of equipment — it requires several components to make the magic happen. Here’s a brief rundown of each component:

• A motherboard is a circuit board that distributes electricity and connects (and facilitates communication with) all other server components.

• The Central Processing Unit (CPU) is like the control center of a server. It executes the instructions provided by the hardware and software on the device.
  

• Memory. The memory of a server is the available storage space. It includes RAM (Random Access Memory), which is temporary storage — it only holds data when the device is connected to power. For permanent storage, hard drives are required.
  

• A hard drive is a piece of hardware that is included in every computer and server. Hard drives store data permanently, even when power is not supplied to them.
  

• Network connection. To function, every server needs a network connection. To do so, servers have an NIC (network interface card) and a physical port or ports. NICs allow communications between computers connected via local area network (LAN) and Internet Protocol (IP).

• Power supply. All servers need to be connected to power. Most computer servers need a power supply of 300 watts or more.

• A Graphics Processing Unit (GPU) renders graphics and videos. Originally used primarily for gaming, GPUs are now commonly used today, for their compute power. 

Knowing how all these underlying components function is an important part of your business operations. Server monitoring — which Splunk can help with — is a critical operation.

Types of servers

With the basics of servers out of the way, let’s look at server types. There are many types of computer servers, and each has specific purposes.

Here are some of the most common types:

Web server

A web server is used to access static web content, like HTML pages, images, and videos, using HTTP (Hypertext Transfer Protocol). 

Proxy server

Proxy servers connect a host server and a client server. After data from a website travels through the proxy's server, it is sent to your computer's IP address. Since the information is requested and then transferred from the source to the proxy server rather than from a client to another user directly, this method adds an extra degree of protection. 

Virtual machine (VM)

Data is connected and stored by virtual machines via virtual space. IT teams utilize software called a hypervisor, or virtual machine monitor (VMM), to build virtual machines. A hypervisor can run hundreds of virtual machines on a single piece of hardware.

As many companies already know: VMs are the most economical kind of servers to operate.

(Learn about virtualization)

Application server

Application servers use virtual server connections to connect clients to software applications. This enables users to access applications without having to download data on their own hardware. Application servers are perfect for organizations because they can efficiently hold large volumes of application data for numerous users.

Domain name system (DNS) server

Whenever users type domain names into a web browser address bar, DNS servers determine the correct IP address. The device is directed to the correct location to access the site's data by the IP address of the website.

(Learn about DNS security.)

Print server

As the name implies, a print server connects remotely to local computers so that users can print from the comfort of their desks.

File Transfer Protocol (FTP) server

File transfers between computers are done via FTP servers. While downloaded files are extracted onto your device from the server, uploaded files travel from your computer to the server. The term "file transfer protocol" also describes the process of securely connecting two computers via a server to exchange data.

Dynamic Host Communication Protocol (DHCP) server

Computer systems that dynamically allocate IP addresses to clients are called dynamic host configuration protocol (DHCP) servers. Because these servers can handle several client requests at once, they’re essential for network administration.

File servers

A machine that offers shareable disks that users on a business’s network can access is called a file server. Usually, file servers are used for storage alone.

Mail server

Using email service platforms, a mail server holds and distributes emails for users. Mail servers are configured to automatically connect to a network, so individual users don't need to run any software to access their email.

Selecting the right server for you

When selecting a server or servers for your business, you need to select one that can accommodate your needs — but not one that is too powerful, ultimately dumping money down the drain. 

Consider these elements to make the best decision for your business:

• Server requirements. What do you need your server(s) to do? Research server specs based on the applications you plan to run.
• Physical type. You can choose between tower, rack, and blade servers.
• Location and maintenance. Where will you house your server(s)? What maintenance will be required?
• Budget. How much can you spend on servers? This calculation should include upkeep costs. 

(Related reading: Moore’s Law & Amdahl’s Law.)