A Network card is a hardware device that uses to connect computers together in Network. The network card is also known as a network adapter. Each computer must have a Network card in order to connect to the network. Most modern computers come with built-in Network cards. If you are using a wireless network you must have a wireless Network interface card to connect to the Network.
A switch is an active device that connects two or more network segments together at same time in a network. Switches have become an increasingly important part of our networking today because nowadays every networks use the Star topology. In star topology a switch is use as the central device. The switch acts as a filtering device by associating the MAC address of the system connected to the switch with the port on the switch. Each switch contains a certain number of ports, typically 8, 16, 24 or 48. Also Switches can be connected to each other to build larger networks. But switch is an expensive device.
Routers are packet-forwarding devices just like switch. Routers allow transmission of data between network segments. Unlike switches, it transmits data packets based on physical node addresses. Router is the device that connects two different networks together. Router is a Network layer device, so it can work with the network packets at a higher level. So how do routers work? In the case of the IP protocol, an IP address is 32 bits long. Those 32 bits contain both the network ID and the host ID of a network device. IP distinguishes between network and host bits by using a subnet mask.
Cabling is the medium for the transmission of data between computers on a Network. In a Network, computers can be connected together using a variety of cable types, such as unshielded twisted-pair, shielded twisted-pair, coaxial, or fiber-optic cables. Each cable type has its own advantages and disadvantages