This unit defines the basic concepts regarding an Internet. Internet is a network of networks where lot of information is obtainable and is meant to be utilized through you. No one owns the Internet. It contains a large number of interconnected autonomous networks which connect millions of computers across the world. The unit defined the various tools obtainable on the Internet & the several services provided through the Internet to users. In this unit we have talked about the Electronic mail Usenet & newsgroups, FTP, Telnet & search engines. We also define the use of frequently asked questions. The unit also defines the significance of Internet addresses. Addresses are necessary for virtually everything we do on the Internet. There are several services obtainable on the Internet for document retrieval. For browsing the Internet there are several browsers obtainable such as Gopher & World Wide Web. Both of these browsers are simple to use and most popular browsing mechanisms on the Internet.