Network hardware, also known as network equipment or computer networking devices, are electronic devices which are required for communication and interaction between devices on a computer network. Specifically, they mediate data transmission in a computer network. Units which are the last receiver or generate data are called hosts or data terminal equipment.
A network interface card (NIC) is a hardware component, typically a circuit board or chip, which is installed on a computer so that it can be connected to a network. A NIC provides a dedicated, full-time connection to a network. Most new computers have a NIC built into the motherboard.
A repeater is an electronic device that receives a signal and retransmits it at a higher level or higher power, or onto the other side of an obstruction, so that the signal can cover longer distances. Repeaters are used in long-distance communication to regenerate signals that have been weakened by attenuation.
A hub is a basic networking device that connects multiple computers or other network devices together. A hub has multiple ports, and when a packet arrives at one port, it is copied to all other ports so that all segments of the LAN can see all packets. Hubs are now largely obsolete and have been replaced by network switches.
A network switch is a computer networking device that connects devices together on a computer network by using packet switching to receive, process, and forward data to the destination device. Unlike a hub, a switch forwards data only to the one or multiple devices that need to receive it, rather than broadcasting the same data out of each of its ports.
A bridge is a network device that connects multiple LANs (local area networks) to form a larger LAN. The process of aggregating networks is called network bridging. A bridge connects different network segments and helps to filter traffic between them. It operates at the data link layer of the OSI model.
A router is a networking device that forwards data packets between computer networks. Routers perform the traffic directing functions on the Internet. Data sent through the internet, such as a web page or email, is in the form of data packets. A packet is typically forwarded from one router to another router through the networks that constitute an internetwork until it reaches its destination node.
A modem (modulator-demodulator) is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data. Modems are used for connecting to the internet over telephone lines.
A gateway is a network node that connects two networks with different transmission protocols together. Gateways are distinct from routers or switches in that they communicate using more than one protocol and can operate at any of the seven layers of the OSI model.
A firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. A firewall typically establishes a barrier between a trusted internal network and an untrusted external network, such as the Internet.
A wireless access point (WAP) is a networking hardware device that allows a Wi-Fi compliant device to connect to a wired network. The WAP usually connects to a router (via a wired network) as a standalone device, but it can also be an integral component of the router itself.