This document discusses network computing concepts including the internet, intranets, extranets, and various tools for communication and collaboration over networks. It explains that the internet links computing resources globally using TCP/IP protocols. Intranets and extranets allow internal and partner communications. Discovery tools like search engines, software agents and portals help access information. Communication occurs through email, chat and social networks. Collaboration is supported by workflows, groupware and real-time tools that allow shared editing. Web applications also enable distance learning and telecommuting.