You can create any number of admin users and assign them 'roles' to grant them access to certain features but not others as appropriate.
From the left menu go to System > Manage users.
CREATE AN ADMIN USER
1. Click on
Add new user button.

2. Enter their name, email address and a password you can choose randomly.
3. Select at least one role.
You can assign a preset role or one you have created (view
Manage roles).
4. Click Submit
5. Click on the Send reset password link so that the user is notified where to login and invited to reset their password.
EDIT AN ADMIN USER
1. Select your chosen admin user.
2. Edit their details.
3. Save the changes by clicking Submit.