Every version of HTML is backwards compatible with previous versions. HTML-formatted documents allow images and hyperlinks to be displayed in documents. The second is typically the address of the computer the data or service is located. Further parts may specify the names of files, the port to connect to, or the text to search for in a database. A URL is always a single unbroken line with no spaces.
Most Web browsers allow the user to specify a URL and connect to that document or service.
In this way, hyperlinks can be made not only to other texts and media, but also to other network services. Web browsers are not simply Web clients, but are also full-featured FTP, Gopher, telnet, email, and newsgroup clients.