In Windows, a shortcut file contains a target to another file on the computer. When you click on a shortcut file, that file locates and opens the target program. The most common types are ".lnk" for Windows applications and ".URL" for web browsers.
An ".lnk" is a shortcut to another file on the computer, usually an ".exe" file. Clicking on an ".lnk" file sends a message to the ".exe" to start and run.
This extension associates with an Internet location. Web browsers use ".URL" files to open websites. Opening a ".URL" file will open the website in your default browser.
Windows generally hides the file extensions on shortcuts, even if you have selected to show extensions for known file types.
The most common places you can find shortcuts in a Windows system is on the desktop or in the "Start" menu. Programs can install shortcuts in these places for easier system navigation.
Both ".lnk" and ".URL" file extensions can become infected. You should scan them regularly as part of a system virus scan.
Many programs use shortcut files with their own extensions, such as ".mat" for Microsoft Access or ".kys" for Adobe programs, but they are usually application-specific, unlike the ".lnk" and ".URL" file extensions.