TCP/IP:

TCP/IP in full Transmission control protocol/Internet protocol, standard internet communications protocols that allow digital computers to communicative over long distances. The internet is a packet- switched network in which information is broken down into small packets, sent individually over many different routes at the same time and then reassembled at the receiving end.

The TCP/IP protocol is designed such that each computer or device in a network has a unique "IP Address" and each IP address can open and communicate over upto 65535 different "ports" for sending and receiving data to or from any other network device. The IP address uniquely identifies the computer or device on the network and a "port number" identifies a specific connection between one computer or device and another.

A TCP/IP "port" can be thought of as a private two-way communications line where the port number is used to identify a unique connection between two devices. The concept is very similar to any other type of port on your pc except that instead of having a physical connection.

Layers:

TCP/IP protocol has four layers.

Layer 1-Link layer

Layer 2-Internet layer

Layer 3-Transport layer

Layer 4-Application layer

The average person on the internet work in a predominately TCP/IP environment. Web browsers, for example- use TCP/IP to communicate with web servers. The transfer of information work so seamlessly that millions of people use TCP/IP everyday to send email, chat online and play online games.