Redmine user accounts connect a person's login, profile details, notification preferences, and project access eligibility. Create an account before a team member needs project membership, issue assignment, watchers, time entries, or wiki edits under their own name.
Administration → Users manages local accounts and shows their activation state. An active account can sign in and be assigned to project work, while registered or locked accounts cannot be used normally until an administrator activates or unlocks them.
Use an initial password path that matches the site's onboarding process. If email delivery is not configured, create the account without relying on generated account-information email and give the user a separate password-reset or onboarding channel after mail is working.
Related: How to create a Redmine group
Related: How to set Redmine role permissions

Leave Administrator unchecked unless the user should have unrestricted access to all Redmine administration and every project.
The initial password must meet the local password policy. Use Generate password only when the site's email delivery path can send the onboarding message.

The user account should open My page or another normal signed-in landing page.