On this page you can Add/Edit permissions. The screen is divided into two parts: Rights (1) and History (2).
In the Rights section (1) you can find information about user rights. The possible permissions are View and Edit. The checkboxes at the end of each row allow you to set user permissions, while the checkboxes at the top give permissions to all users.
In the History section (2) you can see the changes that have been made to the user rights.