URLs (Uniform Resource Locators)
URLs (uniform resource locators), aka web addresses, are strings of characters that represent a reference to a resource. In most web browsers, the URL of a webpage is displayed on top of the browser inside an address bar.
Here is an example of a URL:
URLs are technically a type of URI (uniform resource identifier), but URL and URI are often used interchangeably. URLs are commonly used to reference the location of webpages, but URLs are also used for file transfers, emails, and many other applications. There are a couple different types of URLs.
URLs are specified in RFC 3986, written in 2005, and in a WHATWG URL Living Standard.