A URL is human readable text that was designed to replace the numbers (IP addresses) that computers use to connect with servers. since it is confusing for people, there is a name for it.
Friendly url: mywebsite.com
Your website each page should be human friendly for Seach engines to read, see example below.
Your about us page
mywebsite.com/about-us – correct
mywebsite.com/about_us.php?page=1234 – wrong
They also identify the file structure on the given website. A URL consists of a protocol (https), domain name (your site name), and path (director where the file is saved)