TCP/IP

TCP/IP is a Networking Model named after the two most common protocols used, TCP and IP. It was initially developed by the DoD(Department of Defense) with the help of various volunteers from universites. It is as of today the most used networking model in the world (above 95% of devices use it). This model dictates how devices should communicate with each other with the help of 5 Layers: Physical Layer, Data Link Layer, Network Layer, Transport Layer and Application Layer. With IP and TCP being part of the Network and Transport Layer respectively.

Note

The layers are only rough abstractions for better understanding. Not every protocol can be represented by one specific layer. For example the ARP protocol can be placed in two layers namely in layer two and layer three because it allows the communication between those two layers.

Before TCP/IP became the overall norm the OSI model which was developed be the ISO(International Organization for Standardization) was supposed to be the one and only model. However TCP/IP with the more dynamic approach by letting universities contributer to the project came out ahead.