Networking involves the interconnection of computers and devices to enable communication and resource sharing. It encompasses various technologies such as routers, switches, and protocols like TCP/IP. Networks can be categorized into local area networks (LANs) for limited geographic areas and wide area networks (WANs) for larger geographical spans. Networking facilitates internet connectivity, allowing global communication. Security measures, like firewalls and encryption, are crucial in networking to protect data during transmission and ensure the integrity of information.