IT networking involves the design, implementation, and management of interconnected devices and systems to facilitate communication and resource sharing. This includes local area networks (LANs) for connecting devices within a limited area, wide area networks (WANs) for larger geographical areas, and various topologies like star, bus, ring, and mesh to determine the layout of the network. Key components include routers, switches, modems, access points, and cables, while critical protocols such as TCP/IP, HTTP/HTTPS, FTP, and DNS ensure data is transmitted efficiently and securely.