KMSPico is a tool used to activate Microsoft products, including Windows and Office. It works by emulating a Key Management Service (KMS) server on your local machine. When you run KMSPico, it tricks the software into thinking it’s communicating with a legitimate KMS server, which allows the software to be activated without a valid product key. It’s important to note that using KMSPico may violate Microsoft’s licensing agreements and can pose security risks, so it’s advisable to consider legal alternatives for activation.