A computer network connects two or more computers together to allow sharing of resources and communication between users. A local area network (LAN) connects computers within a single building or site, while a wide area network (WAN) connects multiple LANs over a larger geographic distance. The Internet is a global system of interconnected computer networks that uses standard protocols like TCP/IP to link billions of devices worldwide. Key applications on the Internet include email, file transfer, remote access, and the World Wide Web, which allows accessing and sharing information through web pages on browsers.