What are Computer Servers and What Do They Do?

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Just as restaurants need waiters to take orders and deliver food to customers, the internet needs servers to deliver information to anyone who asks for it.

In this article, I’ll explain what computer servers are in a way you can easily understand.

Meaning of Computer Servers

A computer server is any computer that bears the responsibility of receiving requests and giving services to other computers in a network.

Computer servers are like waiters in a restaurant. When you go to a restaurant, you tell the waiter what you would like to eat. The waiter takes your request to the kitchen and returns to you later with what you ordered. This is how a server functions too.

Other computers in a network make requests, e.g. ask the server for a file. The server looks for the file and then gives it to the computer that asked for it.

How Do Computer Servers Work?

There are various types of computer servers. But to appreciate their differences, you need to know how they work.

A computer server does 3 things basically:

1. Listening to and receiving requests

Computers imitate humans in many ways. This is one of such cases. A server listens to requests at a particular port. A port is like your phone number. If I want to reach you through a phone call, I have to dial your number. 

When your phone rings, you’ll pick up the call and listen to what I have to say. Likewise, other computers connect to a server through a port. Whenever a request is made, the server processes it.

2. Processing requests

Here, the server reads the request and checks if what was requested exists. It also confirms whether or not the person asking is allowed to get what he’s requesting. If yes, the server fetches what was requested. If not, the server denies the request.

3. Granting requests

Finally, the server gives what was asked to the client. This completes the process.

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9 Types of Computer Servers

Now that you know what computer servers are and how they work, it will be easy for you to differentiate between the types of servers.

As you’ll see below, what differentiates one server type from another is what they process, and how they communicate with other computers.

Here are a few things to note: 

• Network simply means a connection of many computers that communicate with each other.

• Client means anybody or anything making a request. Whether it’s you, your browser, or an app, anyone asking a server to give him something is a client.

1. Web servers

These are some of the most widely used computer servers today. Without them, you’ll be unable to visit your favourite websites. Even at this moment, you are reading this post on our website because of a web server somewhere.

What web servers do is simple. They listen for a special type of request called HTTP (hypertext transfer protocol) requests. HTTP is what web browsers like Chrome use to communicate with websites.

For you to view any webpage like this one, your browser (Chrome, Opera Mini, Safari, Firefox, etc) must send an HTTP request to that website’s server. The web server receives your request and checks whether you’re allowed to view the webpage. 

After it confirms that you are allowed to access the page, it fetches the page and sends it to your browser which displays the page for you to see.

2. Application servers

Application servers are very similar to web servers. Sometimes, they are even classified as the same. The key difference is that web servers are specifically for communication between browsers and websites, while application servers are not limited to browser-website communication. Application servers can process other types of requests.

For example, a weather app on your phone can give you up-to-date information about the weather in your area by processing requests specific to your location and accessing the relevant database to return the weather prediction in real time.

3. Database servers

These are also highly important. They’ve been in existence before web servers, and continue to play a critical role in any organization. They work in the same general pattern as every other computer server.

The difference here is that database servers specifically receive data requests (called “data queries”) and give the requested data or data service to authorized clients.

An example is seen in applications like Facebook that require a username and password to log in. Every registered username and password is stored in a database. When you try to log in, the database server receives your login request, checks if your inputs are correct, and grants your login request.

4. File servers

As the name suggests, file servers are servers for files. They hold files and give them to authorized clients who ask for them. File servers communicate with clients using their special network system called file transfer protocol (FTP).

Read also: What is Database Security? Here’s All You Need to Know

5. Mail servers

When last did you send or receive an email? Whether it was this today or ten years ago, you should be grateful for mail servers because they made it possible. Before email, social media apps, and the internet, sending messages via mail was a tedious process.

First, you had to package your message in an envelope, seal it, and then take it to the post office. There, you sign off and post it to the address of your receiver. Depending on your recipient’s location, the mail might travel through different regional offices before it gets to the post office closest to your recipient, from where it can be delivered to your recipient’s mailbox.

But today, thanks to technological advancements in networking, all that can be done in seconds with the help of mail servers.

Mail servers work like post offices. When you send an email, it first goes to your mail server, using a specialised networking system called POP3 (Post Office Protocol 3). This is akin to you going to a post office to send your mail. From your mail server, the email is relayed to your recipient’s mail server through another networking protocol called SMTP (simple message transport protocol). 

After it’s delivered, the recipient can retrieve the mail from his mail server using POP3. The same process applies when someone sends you an email.

6. Messaging servers

Messaging servers are similar to mail servers. The difference is that they send messages, not emails. Popular examples include Facebook Messenger, Whatsapp Messenger, and the like.

Also, a messaging server doesn’t need to relay your message to another messaging server before it can get to your recipient. It sends your message directly to the intended receiver. This is called “point-to-point messaging.”

7. Network services servers

These are usually seen in large enterprises with many computers and workstations. A network service server is a central server that enables other computers in a network to communicate with each other, and, if permitted, with the internet.

An easy way to picture how network service servers work is to think of them as routers. Like your hotspot, you turn it on for other people to access the internet.

If I want to connect to the internet through your hotspot, my device will make a request. If your hotspot accepts my request, it will grant me access to the internet using your mobile data subscription.

Just like this, network servers connect all the devices in an organization’s network for easy collaboration, file sharing, and faster communication.

8. Print servers

A print server controls the printers in a network. This is especially useful in organizations where there are many printers. No particular worker owns any of the printers. All the printers are hooked onto the print server.

Whenever anyone sends a print request, the print server receives it and looks for an unoccupied printer in the network. It then sends the print instructions which the printer follows. This coordination increases productivity as workers don’t have to manually look for an available printer each time.

Also, it’s easier to set print rules across the entire organization, monitor resource usage, and measure outputs, since everything is controlled by one server.

9. Name servers

Name servers are also known as “directory servers.” They act like a map, helping clients pinpoint the exact location of whatever resource they’re looking for. The most widely used name servers are the domain name servers.

Every active website on the internet has a domain name. The domain name is what you type into your browser whenever you want to visit a website. For example, google.com, nairaland.com, etc. 

But have you ever wondered how typing a name takes you to the exact website you requested? The way you use a home or office address to easily locate any destination in a city even if you’ve never been there. The internet has something similar.

Over the internet, every website has a unique IP (internet protocol) address. Domain name servers keep a list of all active domain names and their respective IP addresses. 

When you type in a website address, the domain name server checks its directory to confirm that what you typed in corresponds to an existing name. If it matches a name, it fetches the location so you can be taken to the exact place you want to visit.

Read also: Cache Memory: What it Means and How it Affects Your Gadgets Performance

Parts of a Computer Server

Like every other computer, servers are made of hardware and software components:

1. Server hardware

The hardware provides the physical resources needed for the server to function effectively. Although any computer can be programmed to act like a server, some computers have been specifically designed to perform this role optimally.

The workload of a server can be enormous, depending on the size of the network and the number of requests the server needs to process at any given time. Typical servers have been designed with that in mind. They are durable, fast, and secure.

Parts of server hardware include the processor, power supply unit, cooling system, and outlets for connecting with other devices.

There are 3 major types of server hardware design. They are:

• Tower servers: These are the earliest models. They are large, resembling the CPU of an old desktop computer. All the hardware components are fitted into the tower.

• Rack mounts: They are usually the size of a large pizza box. Rack mounts were created to reduce the size of tower servers.

• Blade technology: Blade technology is sleek. It shows how far technology has advanced, from large towers to small, slender rectangular computing devices. The cooling system and power supply are kept separate, in a box, called a “chassis.” Multiple blades are mounted on the chassis, sharing the same power supply and cooling.

2. Server software

The software instructs the server on what to do, how to process requests, and how to give clients what they ask for. It is the software that determines what role a server will play.

A computer server software contains all instructions, such as the port to listen to, the networking protocol to use, and what type of service requests to process.

There are various server software. A few examples include Windows Server, Apache, Oracle WebLogic Server, etc.

Read also: The Future of IOT (Internet of Things)

Virtual Servers

With virtualization, hardware can be made to run different servers. Normally, each hardware unit can only run the instructions from one type of software at a time.

That means your server will be either a database server, a web server, an application server, or whatever other type of software you install. But with virtualization, you use software to convert your single hardware into multiple virtual machines.

What that means is you can install various software types on a single server hardware.

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Conclusion

Computer servers are the unsung heroes of today’s digital world. These devices are running 24 hours a day, 7 days a week, all through the year.

Without them, all communication over the Internet will be lost. Your favourite apps won’t function and you’ll be unable to login to your social media platforms, or send emails to your loved ones. When next you come across a computer server, give it a thumbs up for making life easier.

Edited by Priscilla Ajayi.