We use this page when we want to assign one or more roles to a user.
On the left side of the page there is a list of all users. By clicking on the user name, on the right side of the list page, the roles assigned to the selected user can be seen.
If we want to delete an assigned role from the selected user, checked the checkbox related to the name of the role, and then click on the
.
If we want to add a new role to the desired user, we click on the 
. In the opened list, check the box(s) related to the role(s) and finally click on the 
.