Not every URL is visible so long.<\/span> Many addresses do not include the file name, but simply pointing to a directory, like this: http:\/\/www.w3schools.com\/<\/a> http:\/\/w3schools.com\/html\/<\/a> When the server receives a request for a directory name instead of a specific file, look in The directory for the default document, typically called index.html.<\/span> So, in fact indirectly, we type in the full address like this (for example, if index.html as default): http:\/\/www.w3schools.com\/index.html<\/a><\/span><\/p>\n The default file name (also referred to as the index file) can vary, and depending on how the server is configured.<\/span> In this example, named index.html, but some servers use the file name default.htm.<\/span> If the site uses a server-side programming to generate the page, the index file may be named index.php or index.asp.<\/span> Another thing to note is that in the first instance, the original URL does not have a slash to indicate it is a directory.<\/span><\/p>\n When the slash is omitted, the server just add one if you find a directory with that name.<\/span> Index file is also useful for security.<\/span> Some servers (depending on their configuration) displays the contents of a directory if a default file is not found.<\/span> One way to prevent people from seeing the files in the directory is to make sure no index file in each directory.<\/span> The server administrator can also add other protection to prevent the directory displayed in the browser.<\/span><\/p>\n