KMSpico is a tool that activates Microsoft Office and Windows products without the need for a legitimate product key. It works by emulating a Key Management Service (KMS) server on your local machine. When you run KMSpico, it tricks Office into thinking it is communicating with a legitimate KMS server, allowing it to bypass activation requirements. This process is generally fast and doesn’t require an internet connection after installation, making it appealing to many users. However, it’s important to note that using such tools can violate Microsoft’s terms of service and may lead to legal consequences.