Configuring Admin UsersFor stores with multiple merchants, there is an option to add administers, with their own access username and password. Different Roles can be created for different types of users.
How to Unlock UsersFor the security of your site, by default a user is given 6 attempts at logging in. If the user fails on the 6th attempt then his/her log in name will be locked.
Sharing Access to Your Magento AccountYour Magento account contains information that can be useful to trusted employees and service providers who help manage your site. As the primary account holder, you have the authority to grant other Magento account holders limited access to your account.