Process began about 4.7 billion years ago. Gravity causes collapse to continue. Cloud shrinks to rapidly rotating disk. Grains collide and grow into dust balls. These collide and grow into progressively larger bodies.
Planets grow by accretion.
Process ended about 4.6 billion years ago. Fusion begins in core of protosun. Sun blows off outer envelope. Super solar wind carries away remains of nebula. Sun is now star visible from outside.