Hello Guys! This article is going to be about some basic Networking Terms.
Moreover, I advise you to read our previous posts about networking for the best experience so here are the links for easy navigation:
1. How Data Travels Over Network? TCP/UDP
2. Domain Name System, IP & MAC Address
3. A Beginner’s Guide To Ports
The server is a device that provides services. It is mostly a computer that contains the files of a website and sends those files when a user requests them.
When you enter a URL in your address bar you are asking for that page to show and it’s not a website that contains the page, it is a computer that has that page stored and this computer is called Server. But its not only limited to websites, but it can also be any device that provides services/information.
In simple words, a computer that uploads data for users is called a server.
A user of a service is called the Client. You are downloading stuff? You are a client. Do you visit a web page? You are client. That’s pretty simple, A computer that downloads something from a server is called a Client.
Whenever we do something the software has to do some processing, right? Yep, and it takes time. But some programs/devices have a feature that can store information about the tasks that the user often does so it can give faster results when the same task is requested by the user.
This process is called Caching and the stored data is called Cache.
Now that a delicious word but a cookie means something totally different in case of networking.
Let’s take an example, I am using Facebook and my mom calls me for lunch so I turn off my data connection and I turn it on after sometime after lunch.
Now I open Facebook again and here is what happens:
Me: Opens Facebook
Facebook: Login to continue
Me: Wtf man? It’s me Exploitway! Do I need to log in every time? I mean this is really annoying mate.
Facebook: But this is a security check, sir! But if you find it annoying then you can show us a cookie instead.
Me: Cookie? What’s that?
Facebook: Every time you log into your Facebook Account we send a small piece of data to you called Cookie. It helps us to identify that it’s you.
Me: Oh that’s cool.
Well yeah, this is what a cookie does, it is sent by a website and stored in your browser. It tells the website about the previous interactions you have made with the website so the website can provide you better services.
5. Address Resolution Protocol (ARP)
Do you guys know what is a LAN? Well “A group of computers which share a common Internet connection is called Local Area Network.” So if 3 computers use the same router they are on LAN.
But there is something interesting about LAN when two computers in a LAN want to connect to each other then IP Address is not sufficient, we need MAC Address too. But as I told you before that when a data packet is sent it contains IP Address and Port number but not the MAC Address. So how they can know MAC Addresses of each other? Well, that’s where Address Resolution Protocol comes into play.
Let’s imagine two computers A and B are in a LAN and Computer A wants to connect to Computer B so can A connect directly to B? No. They have to verify if this is the same computer they want to connect to.
Let’s see how it works:
1. Computer A sends an ARP request it’s like asking “Hi! I was looking for a computer with IP Address 192.168.42.4 and I think that’s you! And it looks like we are in a LAN so can you please tell me whats your MAC Address?
2. Computer B sends him a confirmation like “Yeah bro! That’s me and here is my MAC Address”.
3. Computer A “Yeah now we can establish a connection” and then Computer A builds a cache where it can store the MAC Address of Computer B so that it can connect faster next time.
This is what ARP does, it asks for MAC Address before connection if the target computer is in LAN.
I hope you guys enjoyed this article about networking terms.
Thanks for reading.
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