This document discusses key concepts related to using the internet and web browsers: 1) A web browser is the program, such as Internet Explorer, Firefox, Safari, or Chrome, that allows users to access websites on the World Wide Web. 2) The World Wide Web consists of all websites and webpages accessible over the Internet through an internet connection. 3) A homepage is the first page that loads when a web browser is opened, which can be customized by the user, while a URL bar displays the web address of the current webpage.