In any ERP system, it is important that you completely understand how users and user access rights are managed. When Odoo is first installed, an admin account is created automatically. This is a superuser account, and it is the only one like it. In some systems, any account can be specified to have full administration privileges. Odoo, however, gives permissions to the administration account that no other user in the system has.
Specifically, all access rights are bypassed when using the administrator account. Much like the root account in Linux or Ubuntu, you always need to protect your administration account by using a strong password and keeping it secret.