Basic hardware components(Computer Network)

All networks are built from basic building blocks of the network nodes to connect, such as network interface cards (NICs), bridges, hubs, switches and routers. In addition, a method of connecting these building blocks, usually in the form of galvanic cable (usually Category 5 cable). Less common are microwave links (as in IEEE 802.12) or optical cables (optical fiber). Ethernet card may be required.
Network interface cards

A network card, network adapter or NIC (network interface) is part of computer hardware designed for computers to communicate through a computer network. It provides physical access to the network environment and often provides low-level addressing system through the use of MAC addresses.
Switches

Switches, routers and bridges, and distribute the traffic load or application content (eg a Web URL identifier) devices is a marketing term. Switches one or more (that is, from beginning to end) physical, data link, network or transport layers, including the OSI model, can operate. Multiple layers of activity at the same time that a device called a multi-layer switch.
Bad “key” is defined in terms that try to understand the first network Overemphasizing often leads to confusion. Many experienced network designers and operators, equipment not related to only one protocol level, each with a logic that are covered by OSI recommended starting. Multilayer device selection by the selection of the applications in question could lead to an advanced topic, but it is not only a multi-layer switching, real-world design concept.