A network card is a piece of hardware that acts as the interface for a computer to a network. This way, computers can communicate across a network. Businesses can cut operation costs with networking cards. Instead of purchasing equipment for each employee, business owners can buy a single piece of business equipment to be shared like desktop printers. A computer network card also makes it easy for IT personnel and computer owners to troubleshoot problems. These cards have indicator lights built in to let you know if there is a communication problem.