Network

Network (computer science), a system used to link two or more computers.
Network users are able to share files, printers, and other resources; send electronic messages; and run programs on other computers.

A network has three layers of components: application software, network software, and network hardware.
Application software consists of computer programs that interface with network users and permit the sharing of information, such as files, graphics, and video, and resources, such as printers and disks.
One type of application software is called client-server.
Client computers send requests for information or requests to use resources to other computers, called servers, that control data and applications.

Another type of application software is called peer-to-peer. In a peer-to-peer network, computers send messages and requests directly to one another without a server intermediary.

Network software consists of computer programs that establish protocols, or rules, for computers to talk to one another.

These protocols are carried out by sending and receiving formatted instructions of data called packets.

Protocols make logical connections between network applications, direct the movement of packets through the physical network, and minimize the possibility of collisions between packets sent at the same time.

Network hardware is made up of the physical components that connect computers.
Two important components are the transmission media that carry;
the computer's signals,
typically on wires or fiber-optic cables,
the network adapter,
Which accesses the physical media that link computers, receives packets from network software,
and transmits instructions and requests to other computers.

Transmitted information is in the form of binary digits, or bits (1s and 0s), which the computer's electronic circuitry can process.