What is Server: Where, How and Why to Build Server

Internet started its journey in early 1960s in form of ARPANET by efforts of US Department of Defense. Along the way to its development, the most common purpose of Internet was data transfer or data exchanging. All data are not of the same kinds.

So, their exchanging Channels are also not the same. Such different channels are called PROTOCOL. But transmitting data by using a Protocol occurs over a most common Model. That is Server Client Model. In brief, lion’s share of data transmission through Internet follows this model.

Now question, what is this Server-client model?

Let’s first have a look at the water supply system  in a high-rise residential building. Here a water tank is positioned on top of the roof. There are many water taps fixed up with every point in bathroom, kitchen, basin etc.of every apartment connected with water-passable steel or plastic pipe. This is Water-Supply-Network.

In this network, the TANK works as a Server and every point with Water-tap is Client. When any tap is opened (Client request), Water comes out from Tank (Server response) This is Server-Client model.

What is Server focus image


In the worldwide Internet system, every computer is connected with another via cable (simply). But data transmission between any two randomly is not so easy and logical. So Server-Client model  is developed which structures that a computer will be Server and all other may/will be Client. If Client Computer requests for data following specific URL, Server computer will respond to and send the same to user. About whole of the Internetting activities go centering round this Server-Client Model.

But, it is necessary that SERVERS be equipped with necessary hardware, software with definite rules  and CLIENT with definite application to make a certain type of data transmission possible. Now question—

What is Server (Server-Client Model)


QUESTION: Is there any other data transmission model beyond this Server-Client Model?

ANSWER: Certainly. Another is P2P Model or Peer to Peer Model. In P2P network, two computers or systems are connected with each other with internet. Files are shared between the systems where there is no central Server. Actually in P2P Model, both the systems are Servers and at the same time Client. When system A (client) requests, B is server and B (client) sends request, A is server.

What is Server

QUESTION: We got a lucid understanding of Servers from the above example; but what is Server’s definition? Or, theoretically what is Server?

ANSWER: In Netplanter, we always emphasize example and clarification rather than definition. It is high time we defined Servers

So, Let’s consider the followings—

  • A Server is a program in computer that stores data or resources to transmit to other computer programs as well as to users (Client) as per request from them through definite protocol.
  • Outwardly, the physical computer that stores data in data center to serve to other Client computer via definite program is also popularly referred to as Servers.

So, we see that Server’s Definition essentially include a component and that is CLIENT. Without Client, a Server is incomplete which is a part of Server-Client Model discussed previously.

So, a Server must have the following characteristics—

  • It is a computer (machine)
  • It stores, delivers and, in some cases, receives a definite type of data.
  • It must have definite software installed for definite data type.
  • It follows a certain Protocol.
  • It must have a Client that refers to actually a PROGRAM run by User’s device.
  • It will work via Certain Port (Port Number)

QUESTION: Is data transmission through Server-Client structure applicable only in Internet and/or WAN (Wide Area Network) infrastructure? In other words, is Servers built only in WAN?

ANSWER: No. You can build Servers at home or in office in LAN (Local Area Network) framework with one or more Clients; with or without being connected with Internet.

Suppose there are three PCs and a laptop in your office. You want to share files among your devices. you can easily build such a Server-Client structure. Make one PC (Suppose the PC on your desk) your Server in which all of the important files, folders and official documents are stored in Hard Drive. Make three other devices your Clients that are located in different rooms. Now connect the devices with a Router with Ethernet cable and perform definite configuration. This way, you can excellently build up a Server with local cable connection. In your small network, Any of your client computers can reach the files and folders stored in Hard Drives of your Server as if they were the parts of client computers.

This is a simple example of Server in LAN built in a very easily visible and understandable way.

However, we’re shortly going to contribute such a step by step process of building LAN-based Server-Client network in our next tutorial.

QUESTION: Then what is the difference between this LAN-based Servers and Internet-based commercial Servers that provide service to thousands of clients?

ANSWER: If we consider the fact from the very root level, we can declare with great confidence that there is no difference between the two.

In LAN, all the associated computers are connected with cable. Same is the case in Internet. Whether you see or not, in Internet system, all the computers of the world are connected with cables that pass through the bottom of sea/ocean by Submarine line.

LAN computers are identified by Computer name or IP Address. On the contrary, internetted Computer Servers are identified by Domain Name which is, in a word, user-friendly version of IP Address.

In LAN, folders in Servers are identified and shared by folder name. But in Internet, there is a universal folder naming system and that is called Website. As a matter of fact, a website is a big folder which is unique for the uniqueness of its Domain Name. So, anything wrong about our declaration?

Contextually, our aim, in this tutorial, is to show up Server building process that is not LAN-based but part of whole Internet system.

QUESTION: Yes, something wrong, please. My computer here in Canada and my friend’s computer at Australia are connected with the same network INTERNET. Can I access folders in my friend’s Hard Drive without building up Server-Client structure?
ANSWER: Certainly you can. For this, two computers must be open and connected with internet. But beforehand both must perform necessary setting and configuration and allow other computer to share resources. But most crucial fact in this case is the IP Address. Both Computer must have Public and/or Static IP Address unless they are connected with the same Home Network. Check out our details on IP Address linked below—

IP Address: Transparent Your Understanding in 10 Minutes

In this way you can share, open, copy-paste and move files/folders from your friend’s HD as if it were in your own computer.

QUESTION:  This means we can directly enter a remote desktop through Internet? Then why do we need Browser to enter a site whose files are stored in remote Servers (computer)?
ANSWER: The reality in Internet world is different. There are numerous type of devices around the world with different structures, Versions, Operating Systems and Companies. One is not/may not be compatible with others. In other words, One device may not be able to recognize others’ language. As a result a common language for web resources transmission was developed which is called html [Hypertext Markup Language]. In this case, Web Servers don’t send text or image but their html form on Browser’s request. Browser translate html into our understandable language. This process is supported by any devices of the world.

Different Servers Types

QUESTION: You mentioned above- a server transmits a certain type of data. My question is: How many types of data are there? Are there different Servers for each kinds of data? How many types of Servers are there?

ANSWER: Timely question indeed! First, here data refers to what resources we use, send and receive in form of text, image, video, animation, mail etc. Considering nature of resources (data) and most convenient way to transfer such data type, different types of Servers are developed throughout the history of Internet.

The followings chart enlists most important Servers types among many other possibilities—
  • Web Servers
  • FTP Servers
  • Mail Servers
  • News Servers
  • Telnet Servers
  • Virtual Servers
  • Application Servers
  • Proxy Servers
  • List Servers
  • Chat Servers
  • Audio/Video Servers
  • Game Servers etc.

Illustration of each kinds of Servers is not part of current post. All these are clarified in my another post. Here is the link—

QUESTION: Which servers transfer what sort of resources? Which software and Ports do they need?
ANSWER: Actually, all these servers are not of parallel type. Their purpose, background and working fields are different. So, it is impossible to discuss them from a common perspective. For details, follow the link above.

However, the chart below best shows the relationship among different factors of a number of basic Servers which can be considered parallel in respect of their purposes and functions.

Servers Transfer Software Protocol Port Client
Web Servers Web page Apache, IIS… HTTP 80 Browser
FTP Servers Files FileZilla Server, Xlight FTP Server etc. FTP 21/22 Browser/FTP Client
Mail Servers E-mail hMail Server, iRedMail etc. SMTP, POP3, IMAP 25 Browser, GMAIL, MAILBOX,

QUESTION: Please explain how do these servers work?

ANSWER: Sure. Let’s explain these one by one—

Web Server

If any person knows at least one server name that is Web Server. Many a man thinks server means Web Server. However, on an average, internet users interact most with Web Servers. Consequently it is easy to understand server by learning Web Servers.
After Berners-Lee invented WWW (World Wide Web) in 1989, Web Server as well as Website technology started its journey bringing about a miraculous revolution in internet activity. Today there are about 1.5 billion websites (2018) around the world of which about 200 million are active. Each of these websites is hosted by one or other Web Server.

If we build up a website, we usually store our websites files (prepared in web language html, css, php etc.) in a commercial Web Server by purchasing their Hosting Plan. We also use a purchased unique Domain Name to identify our Web Servers and our site stored there.

Popular Web Servers software are Apache, Microsoft’s IIS, Nginx, lighttpd etc. Web Servers companies use one of them to build their servers. Web Servers transfer data (webpage) through HTTP [Hypertext Transfer Protocol] that works through Port 80. Web Server’s Client Program is Browser like Mozilla, Google Chrome, Opera, Safari etc.

When a user requests a webpage by typing a URL (formed of Domain Name) in Browser, the Web Servers respond to the request and sends the requested html files to the browser. The Browser translate this file into our understandable language.
Check out details of Web Servers here—

Web Servers Basic- The Must-know Things For Beginners

FTP Server

Web Servers are used only for file transfer which means uploading and downloading files and folders. Unlike Web Servers, File Servers don’t allow you to display or interact with files; rather, this technology is used for speedy movement of files from Servers to Client and vice versa. You can transfer files through web servers (http) channel also. But if the story is about transferring file alone; then, FTP is the fastest medium as it is especially structured for this purpose.

FTP is one of the oldest resources transmission technology that started long before web server technology did. FileZilla Server, Xlight FTP Server, Complete FTP, Core FTP Server, vsftpd, proFTPD etc. are most commonly used FTP software. FTP Servers respond to Client request through ftp (File Transfer Protocol) and Port 21 or 22.  You can access FTP Servers or FTP site by Browser or other FTP Client like FileZilla, Cyberduck, CrossFTP, WinSCP, CuteFTP etc. FTP URL starts with ftp such as ftp://alphabroadway.com.

Check out details of Web Server here—

Using FTP Servers: File Transfer channel you might not be conscious of

Mail Server

Mail Servers are used to receive, store and send emails between Servers and Clients. Everyday millions of email are sent and received throughout the world via Internet. These emails are received , stored and delivered by Mail Server. Most popular Mail Server software are hMail Server, iRedMail, Kolab, Zimbra etc.
Standard protocol used for mail-transfer is SMTP [Simple Mail Transfer Protocol] which works through Port 25, 2525 and 465.
Beyond SMTP, most commonly used other mail transfer protocols are POP3 [Post Office Protocol version 3] and IMAP [Internet Message Access Protocol]. Working on Port 110 and 995, POP3 protocol is specially used  for receiving emails in Downloaded form in Client computer which are saved for offline reading later on. But POP3 protocol restricts client access to mail box from different devices located in different places.
Unlike POP3, IMAP using Port 143 and 993 allows multiple users and give client access to emails from different locations. Reasonably IMAP is the more powerful powerful than POP3. But both POP3 and IMAP is actually used to retrieve emails from definite Server. The main difference between these two and SMTP is that POP3/IMAP serves to retrieve stored emails from Servers to Client only. On the contrary, SMTP which is the latest development of protocol all out purposes including sending outgoing mails between Server and Client and even Servers to Servers.

Other Servers

  • Application Servers: It is usually used in big organizations or institutions or Banks to share same application(s) between users and their database to perform a common task or manage transactional accounts by multiple users.
  • Print Servers: It is used to share a printer among client computers usually connected with a Local Area Network.
  • Virtual Servers: In a word, Servers within Server. When physical Servers consist of many virtually set up servers each of which acts as a full Server, it is called Virtual Servers.

It’s all. Hope you all enjoyed this post. Please leave a comment below reflecting your thought and opinion on the post topic. Also let your friend know by sharing.

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