iTwin Design Review supports two separate workflows: Ad Hoc and Digital Twin.

What is the difference between Ad Hoc Design Review and Digital Twin Design Review workflow? 

The Ad Hoc workflow is for quick, peer reviews on work-in-progress deliverables. This is a great way for project team members to get quick feedback from colleagues on the design on which they are working.

The Digital Twin workflow is for project coordination. In this workflow, all designers are working on a managed project and design reviews are performed on the federated project model throughout the project as the design is being updated.

The review tools within iTwin Design Review are are available for both workflows and both workflows can be utilized together to meet the needs of your specific project and users. 

The table below gives details on what capabilities are available for each workflow.