Most computers are equipped with Ethernet 10/100Base-T network interface cards, enabling communication over the LAN cable. In case a PC has no such card, it should be bought and installed.
At the same time there exist various ways for setting up a computer network. If two PCs are to be linked, this may be done by means of Serial ports (so called Nullmodem), Parallel ports, or USB-to-USB cable. Though it will not be a full-function local area network, some network tasks can be solved.
Local area networks are divided by materials they are made of. The following variants may be used – a coaxial cable, a twisted pair, RadioEthernet (radio waves act as a signal carrier), fibre-optical cable. In order for a PC to work in such networks it should be equipped with corresponding network interface cards (NIC).
