URL is an acronym for Universal Resource Locator. A URL is the full address you use to make a request over the internet. The most common request is requesting a web page from a server when visiting a website in your browser.
At a minimum, a URL consists of the protocol to be used in the request, followed by a domain name. The most commonly used protocols are
https, used for visiting websites. Another protocol which utilises URLs is
ftp used to transer files across the internet.
A simple URL example is http://phoenixweb.com.au. The syntax of this URL is
URLs can also include the following elements:
- Path to a file within the domain
- A port number. This is almost never used as almost all web servers use port 80. Web browsers use this port by default.
An example which includes all those elements is http://phoenixweb.com.au:80/wp-content/uploads/2016/09/red-locker-rows-coloured-locks.jpg which is the URL of the image at the top of the page. The syntax for that URL is
The term URL is often used interchangeably with domain but they are not quite the same thing. As you can see in the explanation above, the domain is just one part of a URL, albeit the most important part.
Read more about URLs at this Oracle definition and this W3Schools page.