What would happen if all of a sudden we could not use names to find a contact number that was saved on our devices? What a painstaking process it would be to remember all those Phone numbers. We humans could easily remember a name (even better if it is a woman). So basically every device and server (which is also a computer) has an IP address, it is a basic need if you want to communicate through the internet. An IP would look like this 76.76.21.21 and you think it's easier to remember this rather than hashnode.com (actually its host) or this 142.250.183.78 rather than youtube.com.

THE WORLD WIDE WEB (www)

The need to send the address of files on the internet came into the picture, World Wide Web. The World Wide Web is just a collection of all web pages that are hosted on a server and can be accessed through a URL (Uniform Resource Locator).

A URL is just like your name given to contacts. URL is the name given to a particular IP address. These URLs later resolve back into IP addresses using a Domain Name System (DNS). We will look into this in detail later.

This IP address belongs to servers that host webpages, so it is the address of web pages too and WWW is a collection of all of these webpages.

WWW was developed by Tim Berners-Lee and this was the first website: info.cern.ch/hypertext/WWW/TheProject.html

WWW works on a protocol called Hypertext Transfer Protocol (HTTP). This allows us to send, receive and redirect to websites using links.

PROTOCOLS

These are pre-determined sets of rules which regulate how the data is transferred. For example, If I am on a video call then it is okay if I lose some of the frames or face a lag as long as the connection is not terminated due to this, but while sending an Email there should not be any loss of data.

So who decides these sets of rules? The Internet Society, this organization is responsible for the maintenance of these protocols and for creating new protocols with a rising need for them. Website: internetsociety.org

Even we can define our protocols and submit them to the Internet Society using RFC (Request to Commit).

Apart from protocols we also need addresses to deliver the data.

PHYSICAL ADDRESS

Known by many names: Layer 2 address, Burnt down address and MAC address.

So Network Interface Card i.e. your Bluetooth and Wi-Fi components have their addresses which are permanent and thus known as the Burnt down address. Through these components, your data is sent and received over a network. You have a different MAC address for Bluetooth and Wi-Fi.

It is called the Media Access Control address (MAC address) as it controls the frames (data) received by the device. We will see why it is called a Layer 2 address in the Practical video.

It is a part of IEEE Protocol. ​

It is a 48-bit hexadecimal no. i.e. over 281 Trillion combinations. It is represented by FF:FF:FF:FF:FF:FF E.g. 00:1B:44:11:3A:B7 ​

It allows the Data Link Layer to perform error checks and data integrity.​ We have Layers coming up soon, STAY TUNED!

LOGICAL ADDRESS

Also called Layer 3 address and IP address.

Every Device that can use/communicate over the internet has an IP address, it has format x.x.x.x and every x can have numbers 0 to 255. Thus up to 4.3 Billion variations. E.g. 192.165.0.1​

This is Dynamically assigned to devices in the network by the router using Dynamic Host Control Protocol (DHCP).

We will look at why it is called a Layer 3 address in the practical video.

So Google or any other server is just a computer to which we send requests, so it is an IP address. So just like phone numbers we store them as names.. we cover IP addresses by names, precisely URLs.​

So when a request is made from a client, HTTP carries the URL of the website to the DNS server, which in return gives back the IP address of the website's server.​

We will cover more after the OSI model.​

Moving to the Question Of The Blog, if suppose multiple browser tabs are open running different websites or different instances of the same website, how does our device know where the specific data is to be given when received?

Follow the video lectures on YouTube CLICK HERE!!!

In the next blog, we will cover Models and Layers. Coming Soon. Follow the Blog! Do Like & Follow the Blog for upcoming blogs, do visit my Youtube channel for video explanations, Kshitij Khanka. For any doubts or queries the comment section is always open until then, see you folks on the next blog.