The very basics of TCP/IP - Layers and what they do

Source: Security Protocols

Introduction – what is TCP/IP TCP/IP stands for Transmission Control Protocol/Internet Protocol and is the system of standard protocols that runs the web. That is to say, any computer that wants to send WWW information to another via the internet will almost certainly want to use TCP/IP as the transmission protocol, and understanding it is the key to understand the ‘lower levels’ of how the internet works. Though keep in mind that other protocols such as SMTP and FTP take over to control email and some file transfers respectively.

So why do we need one standard system of sending data over the internet? Well the answer is simple, without a uniform way of sending and receiving data, each machine connected to the internet would have its own idea about how to handle data it received and format the data it was sending. Imagine that the situation would be similar to that of someone sending a letter in China to a person in England who had to prior knowledge at all of the Mandarin language, and visa-versa; neither person would have a clue how to read what the other was trying to say. Apply that to computer networks and you can see that no machine would be able to understand what the other was doing and we would have chaos. TCP/IP (and a few others) set out the rules so that everyone does everything in more or less the same way.