Sometimes you just can’t say it any clearer than Microsoft Docs:  

“Group policy objects (GPOs) are used on-premises to configure settings on personal computers, and other on-premises devices. In device management, GPOs help control security and features in the Windows OS, Internet Explorer, Office apps, and more.

Many organizations are looking at cloud solutions to support the growing remote workforce. Group Policy analytics is a tool and feature in Microsoft Endpoint Manager that analyzes your on-premises GPOs. It helps you determine how your GPOs translate in the cloud. The output shows which settings are supported in MDM providers, including Microsoft Intune. It also shows any deprecated settings, or settings not available to MDM providers.”