The Windows key is a key combination that opens Windows and lets you start or stop the computer.
It also lets you access some programs.
It has to be pressed to start a program, and the keys are used to open other windows and access other functions.
The keys have become a bit of a meme, with some people holding the keys in a way that makes them look like keys and others showing them as a keychain.
The Microsoft Store has the Windows key on sale for a cool $5, and a few websites, including Amazon, sell them for about $10.