Internet 101

The internet is a network. Because of that, the internet is not owned by anyone, or we can say it's owned by everyone. Today, there are 1.5 billion websites on the internet and counting. If you were to visit one website per day, it would take you four million years to visit them all. We access websites on the internet using application called browser. The commonly used browsers are Google Chrome, Mozilla Firefox, Internet Explorer and Safari.

Websites content are stored in a special type of computer called servers. Servers are computers in a network that their main function is to provide resources to other devices in a network. Devices that access a server to get resources are called clients. For example when we access a website our laptop, our laptop is a client and we get the web content from a server located somewhere in the world.

Browsers access a server based on its IP address. We will learn what happen behind the scene from the time we enter a website address in a browser until a website shows up on your screen.

Process of Accessing a Website

Typically, when we access a website, we will use the Uniform Resource Locator (URL) that look like this https://youtube.com. However with this address alone, a browser does not know the IP address of the server. For analogy, the URL is like the name of a building, in order to reach the building, you will still to have the address of it.

For that, browsers will first access a system called the Domain Name System (DNS). A domain name system is like a phone book where it contains many website addresses and their IP addresses. The DNS will go through its list and pass the requested website IP address to the browser. Now know the IP, the browser will then make a request to the destination website server to retrieve all the required files to display the website. This process happens in a split second every time you access a web page.

When we access a web page, we usually retrieve files from the server which includes HTML files, CSS files, JavaScript files, images and other media content. HTML, CSS and JavaScript files are the foundation of a web page. Once a browser retrieves these files, they will convert them into web pages that you see.