Over time, a region within the star becomes more dense than its surrounds. At this point, gravity kicks in and the cloud starts to collapse in on itself.

As the cloud shrinks, its centre (or core) becomes very hot and dense. The cloud will start to spin a little as it collapses, forming a disk.

Eventually, the star's core becomes so hot and dense that nuclear fusion begins. This is the actual birth of the star.

The light, heat and particles produced by the new star blow away most of the remaining cloud.

The star is left alone to slowly use up its nuclear fuel before dying in spectacular fashion several million, if not billion, years down the line.