The Partner visa consists of 2 parts: temporary and permanent.
When you first apply for this visa you are actually submitting 2 applications - the first one is the temporary partner visa and the second being the permanent residency application. However it is not guaranteed that you will be granted both visas.
If you are granted the temporary visa then after 2 years you will be contacted again in regards to the permanent visa application you had lodged. At that 2 year mark you will be asked to satisfy another set of criteria before being granted permanent residency.