Your domain password is the password you use to log on to your CPanel. You should change this occasionally to maximize your site security. You should always change your password if you think someone else has access to your account.
To change your domain password:
Click on the Change Password button on the home page.
Enter your current password in the Old Password field.
Enter your new password in the New Password and New Password (again) fields.
Click on the Change your password now! button. Your password has now been changed.