Switching is heavily abstracted away from us when we work in the Cloud. You'll have very little to do with switching, but it's a fundamental networking concept.
The switch is a network device that allows computers to form a local network. Over this local network, the attached computers can send data to each other, which may include images, files, games, and more.
In the modern network, a switch is paired with a router (covered next), to enable talking to other systems in other networks.