When you create a User, you can choose to grant permission for the new User to be able to create/manage other Users and Clients.
To enable this permission, go to Users.
Next, click into the User you want to give the permission to.
Then, click 'Manage Users' (+ 'Manage Clients' if needed)
Click Save
This User now has the ability to add, remove and edit other Users.
Click on the link below to watch: