Review Links allow you to share content from your project to external users for review. When adding a Collaborator to a project they have access to all non-private files and folders on that project inside the account.
Sharing files as Review Links offers more control over what the external user is able to interact with as they only have access to the files and folders that have been shared with them.
Adjust permissions on Review Links, such as allowing users to approve clips they're reviewing, choose whether they can access all versions contained in a version stack or just the newest version, enable/disable downloading, enable/disable comments, password protect a Review Link or set an expiration date on the link:
Sharing files and folders as Review Links allows external users to leave comments without the need to create Frame.io accounts. Inviting a user as a Collaborator requires them to create a Frame.io account.
Collaborators are users who have access to the projects you invite them to. They have the ability to upload files, create folders and stack versions. They also have access to receive project notifications such as when a new comment is made or when someone else on the project has uploaded new media.