Whenever one computer is able to communicate with another, this creates a network. Networks can be as small as two computers connected together or as large as the Internet, which spans the globe as the world's largest computer network. Even at a network's smallest size, computers need to have a set of instructions or a common language in order to communicate correctly. This common language is the various network protocols.
Origin
The development of the first network protocols came in the 1970s and 1980s as a means to connect mainframe computers together. Two of the first network protocols were the Internet Protocol, or IP, and the Transmission Control Protocol, or TCP. These two protocols combine as TCP/IP and are still the primary Internet network protocol as of 2011. In fact, several of the protocols originally devised in the 1970s are still used today with only a few revisions, such as SMTP which controls sending emails, and FTP which allows the uploading and downloading of files over the Internet.
Purpose
Without network protocols in place it would be virtually impossible for computers to network and communicate with each other. Without network protocols any communications would need to take into account every single different type of computer, component manufacturer and software developer when trying to connect with another computer. By having a set of standards that all computer communications follow, communications only have to make sure they match those set standards. For example, a computer sending out a data packet over the Internet, such as a request to view a Web page, uses these standards to structure that data packet so that it not only reaches its destination, but will also be understood when it gets there.
Types
Network protocols exist at every level of communication available to a computer. This can be from programs using FTP to send files and POP3 to retrieve email on the application layer, to the protocols used to define specifications for the wiring used to connect the network together on the physical layer. Network protocols can be wide and encompass other protocols, such as TCP, or narrow with a specific focus and purpose, such as FTP.
Usage
Network protocols operate while being virtually invisible to the user. A user doesn't need to do anything special to use a certain protocol. When a user performs a network related action, such as typing a Web page URL into a browser, the computer automatically uses the necessary protocols to communicate with the Web server, retrieve the Web page and deliver it to the browser for display.
Tags: communicate with, network protocols, common language, data packet, first network, first network protocols