CAL (Client Access License) licenses for SharePoint are essential for organizations using SharePoint Server as a central platform for collaboration and content management. These licenses enable legal access for users and devices to SharePoint servers, offering functionalities such as document management, intranet sites, and collaboration features. SharePoint CALs are available in two variants: User CAL and Device CAL. A User CAL allows a single registered user to access the SharePoint server from any device, which is ideal for employees using multiple devices. On the other hand, a Device CAL allows access to the SharePoint server from a specific device, regardless of the number of users using that device, which is beneficial in environments where devices are shared. Additionally, to access advanced SharePoint features such as Enterprise Search or Business Intelligence, SharePoint Enterprise CAL licenses are required, which complement the standard CAL licenses. Choosing the right type of CAL license depends on the needs of the organization and can impact costs and license management. Purchasing the appropriate CAL licenses is crucial for the legal use of SharePoint and ensures compliance with Microsoft licensing regulations.