List important uses of computer network?

Computer networking is the engineering discipline concerned with communication between computer systems or devices. Networking, routers, routing protocols, and networking over the public internet have their specifications defined in documents called RFCs.[1] Computer networking is sometimes considered a sub-discipline of telecommunications, computer science, information technology and/or computer engineering. Computer networks rely heavily upon the theoretical and practical application of these scientific and engineering disciplines. There are three types of networks: 1.Internet. 2.Intranet. 3.Extranet. A computer network is any set of computers or devices connected to each other with the ability to exchange data.[2] Examples of different networks are:

Local area network (LAN), which is usually a small network constrained to a small geographic area. An example of a LAN would be a computer network within a building.
Metropolitan area network (MAN), which is used for medium size area. examples for a city or a state.
Wide area network (WAN) that is usually a larger network that covers a large geographic area.
Wireless LANs and WANs (WLAN & WWAN) are the wireless equivalent of the LAN and WAN.
All networks are interconnected to allow communication with a variety of different kinds of media, including twisted-pair copper wire cable, coaxial cable, optical fiber, power lines and various wireless technologies.[3] The devices can be separated by a few meters (e.g. via Bluetooth) or nearly unlimited distances (e.g. via the interconnections of the Internet[4]).

In the world of computers, networking is the practice of linking two or more computing devices together for the purpose of sharing data. Networks are built with a combination of computer hardware and computer software. Some explanations of networking found in books and tutorials are highly technical, designed for students and professionals, while others are geared more to home and business uses of computer networks.

Wi-Fi is the most popular wireless communication protocol for local area networks. Private home and business networks, and public hotspots, use Wi-Fi to networks computers and other wireless devices to each other and the Internet. Bluetooth is another wireless protocol commonly used in cellular phones and computer peripherals for short range network communication.

Internet Service
The technologies used to connect to the Internet are different than those used for connecting devices on local area network. DSL, cable modem and fiber provide fixed broadband Internet service, while WiMax and LTE additionally support mobile connectivity. In geographic areas where these high-speed options are unavailable, subscribers are forced to use older cellular services, satellite or even dial-up Internet instead.

Computer networking is the engineering discipline concerned with communication between computer systems or devices. Networking, routers, routing protocols, and networking over the public Internet have their specifications defined in documents called RFCs.[1] Computer networking is sometimes considered a sub-discipline of telecommunications, computer science, information technology and/or computer engineering. Computer networks rely heavily upon the theoretical and practical application of these scientific and engineering disciplines. There are three types of networks: 1.Internet. 2.Intranet. 3.Extranet. A computer network is any set of computers or devices connected to each other with the ability to exchange data.[2] Examples of different networks are:

Local area network (LAN), which is usually a small network constrained to a small geographic area. An example of a LAN would be a computer network within a building.