Various Network Protocols.

For the proper functioning of the web and the various activities that are associated with the web such as sending a mail, or uploading a file to the server or for basic communication only, certain rules and regulations have been  formed by regulatory bodies, these rules and regulations are called as "Protocols" that needs to be followed by the web for its smooth functioning.When computers need to communicate they have to be knowing how this communication is going to be established and how the information will be exchanged, what will be the format all these things are described by Protocols.

A more technical definition of Protocol can be given as, In the field of Information Technology, a protocol can be defined as a special set of rules that gets implemented over the network and used by various communicating entities when they communicate.

In this article of mine, we are going to be focussing on various protocols that are available over the web and for what purpose they are used.

• TCP/IP: TCP/IP together is normally referred to define the complete suite of protocols, each with different functions, to carry out the basic operations of the web. However, when we talk about TCP and IP separately, we can say that Whenever we send information over the web the whole information gets broken down into small packets to speed up the transmission since different packets can be sent via different available routes and then can get assembled as a one at the destination.
  
  
1. TCP(Transmission Control Protocol) protocol makes sure that none of the packets gets lost during the transmission and it makes sure that the ordering of data is maintained the data that is sent in which order should also be received in the same order.It is a Connection Oriented Protocol and it maintains the connection until the whole transmission process gets completed.TCP makes sure that before sending the message the receiver is ready for accepting it.


2. IP (Internet Protocol) is the method used to make sure that the information should be sent to the proper address.As we know that every Computer over the network has its own IP address by which they get identified.IP doesn't create the physical connection with other computer and relies on TCP for this purpose, the packets that are sent contains the IP address associated with them to make sure that it reaches the correct destination rather than getting lost in the middle.


• UDP(User DataGram Protocol): A DataGram is same as the packet but sometimes it can contain more than one datagram.UDP performs the same task as TCP does but UDP doesn't give a guarantee of packet transmission, it is doubtful that packet will reach its destination and get lost in middle. UDP is a Connection-Less Protocol, here before sending the message a proper check is not performed that whether the receiver is ready to accept the message or not.


• Mail Protocols: Email requires its own set of protocols for both the purpose of sending and receiving emails.


1. The most common protocol that is used for sending emails is Simple Mail Transfer Protocol(SMTP). SMTP communication between mail server uses port 25, but SSL/TLS encrypted SMTP uses port 465.
2. The most common protocol which is used by computer systems for receiving emails is Post Office Protocol(POP). POP provides end users the capability of fetching emails from mail servers and check their emails in their own system. POP uses port 110, but SSL/TLS encrypted POP uses port 995.


3. Another Powerful Protocol that is used for receiving emails is Internet Message Access Protocol(IMAP). IMAP is the better option - and the recommended option - when you need to check your emails from multiple devices, such as a work laptop, a home computer, or a tablet, smartphone, or other mobile devices. For example if you have some emails using the POP protocol from your computer and if you see the same email again on your mobile phone it won't have been updated as read but on the other hand IMAP updates all these things automatically across various devices.IMAP uses port 143, but SSL/TLS encrypted IMAP uses port 993.IMAP is preferred over POP in a business environment as it provides more flexibility than POP.


• File Transfer Protocol(FTP): It is an old protocol that is used for copying files from one computer to another computer over the network. It is not used very heavily nowadays and just been used for uploading files to websites using File Server such as Filezilla etc. It can also be used for downloading files but nowadays downloading is handled by HTTP protocol.FTP uses port 21.


• Hyper Text Transfer Protocol(HTTP): It is a protocol that is containing all the rules and regulations that are required over the web for establishing communication between client and server, HTTP protocol takes the request of the client by establishing a communication link with the server and then after processing the request at the server, it takes the response generated by the server and makes it visible on the browser of the client. It's secured version is also available as HTTPS. HTTP uses port 80 and HTTPS uses port 443. If you guys want to know more about  HTTP vs HTTPS you can read my article on it.


• SSL/TLS(Secure Socket Layer/Transport Layer Security): SSL and TLS are the security protocol that makes sure that the data that is getting transferred over the web should be secure and should only be delivered to the authentic person and if someone tries to breach the security and tries to read out the data, he won't be able to read any or to modify the actual data. TLS is an updated version of SSL and more secure than SSL.

These were the basic protocols that are used over the web, there are plenty of protocols are there but for a start to have knowledge of these is a must. 

"Internet Assigned Numbers Authority" is the organization that takes care of these protocols and they are the one who controls them.