Network interface cards allow computers to connect to a network and to the Internet. Sometimes they are referred to as Ethernet cards or a network adapters; these terms refer to the same component. Network interface cards are usually part of the motherboard, but they can also be installed as an expansion card. Modern network interface cards can connect to networks via cable with an RJ-45 connector or wireless via Wi-Fi.
Even though network interface cards have evolved significantly throughout the years, they can still be used in older computers without any problems. One of the main advancements has been the speeds which they support, reaching up to 160 gigabits per second as of 2014.
While it's quite simple to create a network of two computers by plugging a cable to their network interface cards, special devices are required in order to connect more than two. A common device used to connect multiple computers to a network is a router, which can run multiple networks at a time — for instance, a home network and an Internet connection — making them highly versatile. Other types of devices used to facilitate connecting multiple computers to the same network are switches, hubs and bridges.