The ‘Users’ tab is where all user rights and roles are managed. Any individual who needs to access a part of the study must be added to the study as a user using their email address.

Only users with the 'Manage users' right can access the ‘Users’ tab. Individual user rights are defined on site level. 

1. The 'Filter users' field can be used to filter the displayed users. This is useful if you have many users and you want to quickly locate a user. The filter works on name / last name only, users cannot be identified by their email address.
2. 'Notify selected users' can be used to send an email to selected or all users in the study.
3. The '+ Add user' button is used to invite new users to participate in the study - more details on how to invite a user to your study are provided here. The 'Edit Roles' button allows the administrator to create and edit existing roles. For more information about user roles, refer to the manual entry for defining user roles.
4. ‘First name’ and ‘Last name’ columns list all of the users' first and last names.
5. The ‘Status’ column displays the status of the user. This can either be "Confirmed" for a user who has already created a Castor account and can access the study, or "Invited" for a user who has not yet created an account. Once the invited user registers their account, the status will change to "Confirmed".
6. ‘Manage rights’ and ‘Site rights’ display the number of the user's management and site rights. This is displayed as 0/0 by default when the user is first added to the study. As additional rights are assigned, the displayed number will increase. See below for details on defining rights for each user. The creator of the study is assigned all user rights by default and is displayed as having 6 rights.
7. The ‘Email’ column shows the email of a user.
8. In the ‘2FA’ column you will be able to see if a user has the two-factor authentication enabled. 
9. By clicking on the cogwheel icon in the ‘Edit rights’ column, a study admin can edit the rights and assign roles. 
10. In the ‘Actions’ column, the users can be deleted by clicking on the X icon. When a user is locked out of Castor by entering a wrong password too many times, a lock icon will appear here next to the user. See also how to unlock a locked account. There also is a button to resend the study invitation.
11. At the bottom of the 'Users' tab, you will find the ‘Rights overviews’ button, which leads to a new page with a summary of all user rights. This provides an overview of all users, their rights for each institute and the date of their last login.