A URL, or Uniform Resource Locator, is the address of an Internet website or webpage. Think of a URL as a street address for the location of information on the Internet. For instance, a complete URL like http://coolexample.com/music, points you to the music page of the coolexample.com website.
Take a look at the anatomy of this URL to better understand how they direct online users to specific information: http://coolexample.com/funky/music.html
http:// = protocol
coolexample = domain name
.com =TLD
/funky/music.html = path
/funky/ = directory
/music.html = file name
A domain name is part of a URL, which stands for Uniform Resource Locator. You can see the visual difference in the following example:
In order for computer networks and servers to “talk to one another,” computers rely on a language made up of numbers and letters called an IP address. Every device that connects to the Internet has a unique IP address and looks something like this:
173.156.6.89 or 2001:569:75e2:f200:d53c:c25c:5d71:7a8e
In order to navigate easily around the web, typing in a long IP address isn’t ideal, or realistic, to an online user. This is the reason why domain names were created – to hide IP addresses with something more memorable. You could consider the domain name as a “nickname” to the IP address.
A URL incorporates the domain name, along with other detailed information, to create a complete address (or “web address”) to direct a browser to a specific page online called a web page. In essence, it’s a set of directions and every web page has a unique one.
A web browser will usually dereference a URL by performing an HTTP request to the specified host, by default on port number 80. URLs using the https scheme require that requests and responses will be made over a secure connection to the website.
Internationalized URL
Internet users are distributed throughout the world using a wide variety of languages and alphabets and expect to be able to create URLs in their own local alphabets. An Internationalized Resource Identifier (IRI) is a form of URL that includes Unicode characters. All modern browsers support IRIs. The parts of the URL requiring special treatment for different alphabets are the domain name and path.
The domain name in the IRI is known as an Internationalized Domain Name (IDN). Web and Internet software automatically convert the domain name into punycodeusable by the Domain Name System; for example, the Chinese URL http://例子.卷筒纸 becomes http://xn--fsqu00a.xn--3lr804guic/. The xn-- indicates that the character was not originally ASCII.
The URL path name can also be specified by the user in the local writing system. If not already encoded, it is converted to UTF-8, and any characters not part of the basic URL character set are escaped as hexadecimal using percent-encoding; for example, the Japanese URL http://example.com/引き割り.html becomes http://example.com/%E5%BC%95%E3%81%8D%E5%89%B2%E3%82%8A.html. The target computer decodes the address and displays the page.