A Webroot activation code is a unique alphanumeric code that is used to activate the Webroot antivirus software. Upon purchasing a Webroot subscription, users are provided with an activation code that serves as a key to unlock the full functionality of the software. The Webroot activation code is typically required during the installation process and is used to associate the software with the user's account. It validates the authenticity of the subscription and enables the user to access features such as real-time scanning.