Hello,

Odoo Python Class : use camelcase for code in api v8, underscore lowercase notation for old api

Usually the first word of the class name is the module name and the second word is the model specifications.

E.g:

class AccountInvoice(models.Model):
    _name = 'account.invoice'     
     ...
class account_invoice(osv.osv):
    _name = 'account.invoice'

As best practice it is better to make the the _name  contain a dot joining words, even if your class name is one word:

class Event(models.Model):
    # Private attributes
    _name = 'event.event'
    _description = 'Event'

You can also check the documentation ...

Hope this could helps