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In the present day scenario, computer networks play a vital role in most of the organizations. Networks provide a very rapid method for sharing and transferring files. One of the greatest benefits of installing a network in an organization is that all the software can be loaded on one computer. This eliminates the need to spend more time and energy for installing updates and tracking files on independent computers throughout the organization. Sharing resources is another benefit of a network. Most organizations cannot afford to install laser printers, fax machines, scanners etc., on each computer in the network. Hence, if these devices are added to a network, they can be shared by many users.

The networking devices that are necessary to configure a network are mentioned below:

Network Interface Card
A network interface card (NIC) is a computer circuit board or card installed in a computer. It provides a physical connection between a computer and the network. Network interface cards provide a dedicated, full-time connection to a network. Each network Interface card has a unique Media Access Control (MAC) address.

Media Access Control (MAC) address is a numerical identifier that is unique for each network interface card (NIC). MAC addresses are 48-bit values expressed as twelve hexadecimal digits, usually divided into hyphen-separated pairs, for example, FF-00-F8-32-13-19. MAC addresses are also referred to as hardware addresses, Ethernet addresses, and universally administered addresses (UAAs).

Hub
A hub is a device used to link computers in a network. It connects computers that have a common architecture, such as Ethernet, ARCnet, FDDI, or Token Ring. All hub-computer connections for a particular network use the same type of cable, which can be twisted-pair, coaxial, or fiber-optic. Hubs are generally used in star topology networks. Token Ring hubs are also known as Multistation Access Units (MSAUs). A hub works on the physical layer of the OSI model. Two types of hubs are available as follows:
Active hub is a central device used to connect computers in a star network. It regenerates and retransmits deteriorated signals on the network.
Passive hub is a central device used to connect computers in a star network. It receives information through one of its ports and sends it to the computers connected to every other port. Therefore, although the information is broadcasted to the network, only the destination computer reads it. A passive hub does not regenerate signals.
Repeater
A repeater is a basic LAN connection device. It allows a network cabling system to extend beyond its
maximum allowed length and reduces distortion by amplifying or regenerating network signals. Repeaters can also be used to connect network segments composed of different media, such as connecting a twisted pair cable segment to a fiber-optic cable segment. A repeater works at the physical layer of the OSI model.

Switch
A switch is a network connectivity device that brings media segments together in a central location. It reads the destination’s MAC address or hardware address from each incoming data packet and forwards the data packet to its destination. This reduces the network traffic. Switches operate at the data-link layer of the OSI model.

Router
A router is a device that routes data packets between computers in different networks. It is used to connect multiple networks, and it determines the path to be taken by each data packet to its destination computer. A router maintains a routing table of the available routes and their conditions. By using this information, along with distance and cost algorithms, the router determines the best path to be taken by the data packets to the destination computer. A router can connect dissimilar networks, such as Ethernet, FDDI, and Token Ring, and route data packets among them. Routers operate at the network layer (layer 3) of the Open Systems Interconnection (OSI) model.

Brouter
A brouter is a combination of a bridge and a router. It is used to connect dissimilar network segments, and it routes only a specific transport protocol such as TCP/IP. A brouter also works as a bridge for all types of packets, passing them on as long as they are not local to the LAN segment from which they have originated.

Bridge
A bridge is an interconnectivity device that connects two local area networks (LANs) or two segments of the same LAN using the same communication protocols and provides address filtering between them. Users can use this device to divide busy networks into segments and reduce network traffic. A bridge broadcasts data packets to all the possible destinations within a specific segment. Bridges operate at the data-link layer of the OSI model.

Gateway
A gateway is a network interconnectivity device that translates different communication protocols and is used to connect dissimilar network technologies. It provides greater functionality than a router or bridge because a gateway functions both as a translator and a router. Gateways are slower than bridges and routers. A gateway is an application layer device.

Modem
Modem stands for Modulator-Demodulator. It is a device that enables a computer to transmit information over standard telephone lines. Since a computer stores information digitally and a telephone line is analog, a modem converts digital signals to analog and vice versa. The conversion of a digital signal to analog is known as modulation and that of an analog signal to digital is known as demodulation.