There are more terms used in connection with the World Wide Web than we have space to cover. If you have a particular term you would like to define, try searching at Wikipedia.
Quick basic definitions:
Internet: This refers to the system of connections and servers that form the network of the World Wide Web.
World Wide Web: The World Wide Web is a worldwide computer network that specializes in making the electronic pages and documents available anywhere 24/7.
Groups on the Web: The Web is made up of information published by many different groups including universities, government agencies, businesses, etc.
URLs: Each Web page has an address called a Universal Resource Locator or URL for short. Domain names are found at the end of web addresses. Domain names give you some idea of who sponsors a web page.