What is an URL file?
A file with .url extension is a website URL shortcut that can be saved to computer with any website address. When it is opened by double clicking, the URL will open the website in default browser and the page will be displayed to user. URL files are usually referred to as shortcut files to websites and are represented by the icon of the default browser. URL files can be opened and edited in any text editor such as Microsoft Notepad, Notepad++, or Apple TextEdit.
URL File Format - More Information
URL files are saved in plain text format and can be opened and viewed in any text editor. These open in the default web browser where user performs other browsing.