Final answer:
The Sun formed from the gravitational collapse of a cold interstellar cloud known as a solar nebula.
Step-by-step explanation:
The Sun formed from the gravitational collapse of a cold interstellar cloud. The interstellar cloud, also known as a solar nebula, is a rotating cloud of gas and dust that contracted under its own gravity. As the solar nebula collapsed, material fell towards the center, where it became more concentrated and hot. The increasing temperatures vaporized most of the solid material that was initially present, leading to the formation of the Sun.