Mars rover snaps photo of dust cloud kicked up by descent stage's crash-landing

The video explains the landing of a rover on the surface, detailing the sky crane's role in safely lowering the rover before it crash lands at a safe distance. It also discusses the dust cloud seen in Curiosity's initial photos, which was caused by the sky crane's crash.

What was the purpose of the sky crane during the rover's landing?

Explain the cause of the dust cloud observed in the rover's initial images.