Partner visas are divided in two categories fiance and De facto/spouse visas.

Fiance visas are given to people that are engage to a permanent resident or citizen of  Australia (sponsor) whom  they have met face to face before the application.

The applicant must be overseas  and the application can be only lodge overseas as well.  

A fiance visa is given for 9 months so the applicant and sponsor  can get married within that time and then apply for a spouse visa in Australia.

De Facto and Spouse visas are for people that are in a marrital relationship,  in aDefacto relation ship for 12 months or in a Defacto registered relationship. 

They could  apply in Australia or overseas depending the location of the applicant.

This visa is given in two parts temporary residency  for two years followed by a permanent residency (after providing relevant evidence) .