Final answer:
In order to log in to the Sitecore back end, a user needs the 'Sitecore Client Users' role assigned to them.
Step-by-step explanation:
What role does a user need to be able to log in to the Sitecore back end?
In order to log in to the Sitecore back end, a user needs to have the role of 'Sitecore Client Users' assigned to them. This role provides the necessary permissions and access to enter the back end of the Sitecore content management system.
The 'Sitecore Client Users' role allows users to perform various tasks within the back end, such as creating and editing content, managing media files, and configuring the site settings. It is an essential role for users who need to access and work with the Sitecore back end.