LNK, Windows File Shortcut (.lnk)
The LNK System file format
LNK files are also known as Shortcut Files that are being used as a reference by Windows to an original file containing the shortcut target type, filename, location, the program that can open the file, and a shortcut key which is optional. A shortcut file can easily be created by clicking the right mouse button on a file the shortcut should be created from. By selecting “Create Shortcut” option the LNK file is created. The icon used for the LNK file is usually the same icon used for the target program with a curled arrow indicating that it's a shortcut.
Technical details of LNK files
LNK files are typically implemented as a small file that comprises of a target GUID or URI to an object or the name of a target program represented by the shortcut. Thus, when clicking on the icon, the program operates just as if the original icon would have been clicked. LNK files with shortcuts to an EXE program file can specify how the program should be run. Those attributes can be set by right-clicking the shortcut file and selecting "Properties". Similar to URL files, the LNK file extension is not shown in the filename, even when the option to hide file extensions is disabled.