WWW stands for the World Wide Web.  It is a service that provides Web users with an easy-to-use, point-and-click interface.  It is simply a computer that connects millions of computers all over the globe.

URL stands for Universal Resource Locator.  It is the address of a file on the Web and also identifies the Internet Service, usually HTTP (Hypertext Transfer Protocol), that handles the file. 

URL addresses have two basic parts: (1) a portion specifying the method of file access, and (2) a portion specifying the web location of the file to be accessed.

HTML stands for Hypertext Markup Language.  It is an evolving language used to create pages on the Internet. It contains text, tags embedded commands and page structure, appearance, and content. You can view the HTML coding of any page on the Internet by clicking on View and Source in any browser.  You can also view HTML coding within your web page by clicking on the HTML tab.