The Web and How it Works
Quite a number of people think that the web also known as the world wide web or www and the internet are the same thing. Although they are closely linked but they are two different systems.
The internet is a huge network of computers all connected together, on the other hand, the world wide web is a collection of web pages found on this network of computers. Your web browser uses the internet to access the web.
Before the invention of the world wide web in 1989 by Sir Tim Bernes-Lee, the internet already existed but essentially the internet started off with the ARPANET in 1969, and throughout the 70’s and the 80’s, it kept growing but there was one problem that it had, it was really difficult for computers to communicate with each other, to share documents between each other and most of the time each computer had their own way of doing things. You can think of this as languages. It is a way of communicating with people from different countries and a language that you don’t know. This problem lead to the creation of the world wide web.
Basically, the concept of the web and how it works provides a simplified view of what happens behind the scene when you view a web page in a web browser on your computer or phone. The web consists of billions of clients and servers connected through wires and wireless networks. The web clients make requests to web servers, the web server receives the request, finds the resources and return the response to the client.
What are Clients and Servers?
Clients are the typical web user’s internet-connected devices like your computer connected to your wi-fi or your phone connected to your mobile network, and a web-accessing software available on those devices(a web browser like chrome or firefox).
Servers are computers that store webpages, sites or apps. When a client’s device wants to access a webpage, a copy of the webpage is downloaded from the server onto the client’s machine to be displayed in the user’s web browser.
However the web is not only about the clients and the servers, there are many parts that make up the web. We will lay emphasis on them below. Nevertheless, lets imagine the web as a road. One end of the road is the client which is like your house and the other end is the server which is a mall you want to get items from.
The Other Parts of the Web
The Internet: Your internet connection allows you to send and receive data on the web. From our case study, it is like the street between your house and the mall.
TCP/IP: Transmission Control Protocol and Internet Protocol are communication protocols that define how data should travel across the web. This is like the transport mechanisms (could be a car, or whatever means you move around) that let you place an order, go to the mall and buy your goods.
DNS: Domain Name Servers are like an address book for websites just as you have a phone book for the contacts on your phone matched with names and numbers. When you type in a web address in your browser, the browser looks at the DNS to find the website’s real address before it can retrieve the website. The browser needs to find out which server the website lives on so it can send HTTP messages to the right place. This is synonymous to searching for the address of the mall so you can access it. Basically, DNS is a directory of names that match with numbers. The numbers, in this case are IP addresses, which computers use to communicate with each other.
HTTP: Hypertext Transfer Protocol is an application protocol that defines a language for clients and servers to speak to each other. At the mall, you would need to communicate to the seller to place an order for your goods so this is like the language you use.
Component Files: A website consists of many different files. these files come in two main types. The code files- websites are built from HTML, CSS and Javascript. The Assets- this includes all other things that make up the website such as images, music, video, e.t.c.
The big question: When you type a web address into your browser, What happens exactly?
When you type a web address like google.com in your web browser,
- The browser goes to the DNS server and finds the real address of the server that the website lives on. In the case of google.com, it’s the google server.
- The browser sends an HTTP request message to the server asking it to send a copy of the website to the client. This message and all the other data sent between the client and the server is sent across your internet connection using TCP/IP.
- If the server approves the client’s request, the server sends the client a “200 OK” message and then starts sending the website’s files to the browser as a series of small chunks called data packets. (the google page starts rendering on your browser).
- The browser assembles the small chunks into a complete website and displays it you. (You can now view the complete website)
We did mention packets above to describe the way data is sent from the server to the client. In a very simplified way, when data is sent across the web, it is sent as thousands of small chunks so that many different web users can download the same website at the same time. If websites were sent as single big chunks, only one user could download one at a time, which would make the web very inefficient.
The world wide web opened up the internet to everyone. It connected the world in a way that was not possible before and made it much easier for people to get information, communicate and share their work and thoughts through social networking sites, blogs and video sharing. The web is still evolving today. Search engines have become better at reading, understanding and processing information.
