"Use REST Service" Privileges

Summary

Which kind a access does the "Use REST Service" Privileges grant a user with?

Content

Almost all the Security roles have a number of "Use REST Service" Privileges included. This even counts for the Hiring Manager role, which as an example has included the "Use REST Service - Recruiting Lists of Values" Privilege.

Do any of you know which kind of access they provide the user with?

Are they needed to be able to list content in drop downs in the system? Or are they needed to be able to use OTBI report? Or are they needed for something completely other purpose?