There are few different kinds of Avatar mentioned in scriptures. One of them is Complete (Poorn) Avatar. This is when GOD takes his complete form and descends to earth. Example of this is when Bhagwan took Ram incarnation or when Bhagwan took Krishn Incarnation. Complete aspect of Bhagwan is also called Par-Brahmn. Bhagwan is also called Narayan or Sada Shiv. These are the aspect of Bhagwan when all his qualities are revealed. Other Avatars like Parshuram incarnation is when not all Godly qualities are revealed. This kind of incarnation is called Ansh-Avtar. This is also when Bhagwan stays in his abode and doesn’t have to leave Satya Lok.