Computer networks are critical parts of almost every organization. Administrators of networks and computer systems are responsible for the day-to-day operation of these networks. They organize, install, and maintain the organization’s computer systems, including local area networks (LANs), wide area networks (WANs), network segments, intranets, and other data communications systems. Administrators manage the organization’s servers, desktop and mobile equipment. They ensure that email and data storage networks work properly. They also make sure that employee workstations operate efficiently and remain connected to the central computer network. In some cases, administrators help network architects design and analyze network models. They are also involved in making decisions about future hardware or software purchases to upgrade their organization’s network. Some administrators provide technical support to computer users, and may also supervise computer support specialists who help solve user problems.
As with many technical roles, network administrator positions require extensive technical knowledge and the ability to quickly master the intricacies of new network and server software packages. In smaller organizations, the more senior network engineer role is sometimes associated with network administrator duties. It is common for smaller organizations to outsource this function.
A computer network is a telecommunications network that allows computers to exchange data. In computer networks, networked computing devices communicate with each other via network links (data connections). Connections between nodes are established using cable or wireless media. The best known computer network is the Internet.
The networked computer devices that initiate, route, and terminate data are called network nodes. Nodes can include hosts such as personal computers, cell phones, servers, and network equipment. Two such devices can be said to be networked when one device can exchange information with another device, whether or not they have a direct connection to each other.
Computer networks vary in the transmission medium used to transmit their signals, the communication protocols for organizing network traffic, the size of the network, the topology, and the organizational intent. In most cases, communication protocols are layered on top of (i.e., operate using) other more specific or more general communication protocols, with the exception of the physical layer, which is directly related to the transmission medium.
Computer networks support a myriad of applications, such as access to the World Wide Web, video, digital audio, application and storage server sharing, printers and faxes, use of e-mail and instant messaging applications, and many others.