Device-based and user-based licensing are two licensing options for Microsoft Intune. The main difference between them is how the licenses are assigned and which features are included.

Device-based licensing means that licenses are assigned to specific devices, regardless of the number of users who access the device. With device-based licensing, each device that is managed by Intune requires a separate license, regardless of how many users access that device. Device-based licensing includes basic management features such as device enrollment, policy management, and app management.

User-based licensing means that licenses are assigned to individual users, regardless of the number of devices they use. With user-based licensing, each user who needs access to corporate data and resources on their device requires a license. User-based licensing includes advanced management features such as conditional access, mobile threat defense, and reporting and analytics. In general, device-based licensing is more cost-effective for organizations that have multiple users sharing a single device, such as shift workers, while user-based licensing is more cost-effective for organizations where users need to access corporate resources from multiple devices, such as smartphones, tablets, and laptops.

It's also worth noting that Microsoft Intune offers a hybrid licensing option, which allows organizations to mix and match device-based and user-based licenses, depending on their specific needs. This can provide organizations with more flexibility and cost-effectiveness when managing their mobile devices and applications.