The initial page on the Web site, where everyone starts, is called the Home page. The Web is self-publishing at its best, and worst. Anyone can put up a Web page on any subject they wish, saying anything they want. There are few checks and balances. A domain name may identify the owner of the site or its subject.
File names are usually case sensitive.
Whenever doing research, remember that when you find that needle in the Web haystack, it may not be a needle. There is a lot of irrelevant, useless, and plain incorrect information on the Web. Make sure to evaluate WHO is the publisher of the site when weighing the relevance of the information you've found. This is often called the top-level domain name. Most domains in the U.S. don't use the country code, and neither do many domains in other countries.