What is the difference between a Vipassana Jhana and a Samatha Jhana?

Definitions of the term Jhana tend to emphasize the 'mind state' quality it refers to in various states of meditative absorption: > The jhanas are altered states of consciousness which are produced from periods of strong concentration. Dhamma Wiki > > In Buddhism, it is a series of cultivated states of mind, which lead to "state of perfect equanimity and awareness (upekkhii-sati-piirisuddhl)." Wikipedia So in the context of Samatha (concentration) meditation, Jhana states naturally arise as a consequence of concentration. What I'm struggling to understand is the term 'Vipassana Jhana'. Is it a state of mind that arises from insight or a state of mind conducive to insight?