Models have structural attributes for defining their behavior. These are prefixed with an underscore. The most important model is _name, as this defines the internal global identifier. Odoo creates the database table with this _name attribute. For example, if you provide _name="library.book", then the Odoo ORM will create the library_book table in the database. This is why the _name attribute must be unique across Odoo.
There are two other attributes that we can use on a model: one to set the field that's used as a representation or title for the records, and another to set the order in which the records are presented.