Security access in Odoo is configured through security groups: permissions are given
to groups and then groups are assigned to users. Odoo has a lot of groups. Once
you know about groups, you can select groups from the list of groups. Security is
a major concern when an application is considered. We can control what the user
can do and what users 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..