Security is a major concern when an application is considered. We can control what user can do and what user can't-do on a different level. Control independently each of the four basic operations: read, write, create, and unlink. I.e. allow only read, allow only create, grant permission to create or delete only. Also, we can hide fields or menus for some users and show them for others, make fields read-only for some users and make them editable for others. We use groups to control users.
Go to Settings > Groups
Odoo has a lot of groups. Once you know about groups, you can select groups from list of groups as shown in above figure. For example, let examine Inventory/Manager. You can select this group by scrolling down.
Here you can see, you can add as many as users under Users tab so that only that users can view Inventory.


Access Security in Odoo