Hardware includes the cable and a Hub/Switch that will connect the participating computers together. Printers or any other peripherals connected to one computer can be shared across on any terminal on the network. Typically, each computer requires a LAN (or Ethernet) Card to be installed in it. To this LAN Card the cable is attached, with the other end terminating in the Hub/Switch. A Hub/Switch is a device which connects different computer cables and allows communication between various computers of the network. You could also say that the Hub acts as a policeman, standing on a busy crossroad, directing traffic. Similarly, the Hub directs traffic (here data) between various computers, allowing uninterrupted flow of information from one point to the other.
Over the years, new computers have the LAN card inbuilt on the motherboard. Also wireless LAN cards and Switches /Routers are now available, which facilitate and permit the transmission of data from one system to other without the need of laying down cumbersome wires