The domain name suffix is assigned based on the type of organization. The second part of a URL is typically the address of the computer where the data or service is located. Additional parts may specify the names of files, the port to connect to, or the text to search for in a database. Http is the method by which HTML files are transferred over the Web. For more information about URLs, read NCSA's Beginner's Guide to URLs.
Search engines break down into two categories, directories and indexes.
Directories are good at identifying general information. They group websites together under similar categories, such as Internet tutorials, English universities and Paris museums. The results of your search will be a list of websites that cover the subject you are searching for. But let's say you want more specific information. Web indexes are the way to go, because they search all the contents of a site, not just the file name.