Why was the discovery of fire an important milestone?

Fire occurs naturally in nature quite often- when volcanoes erupt, or lightning strikes or the sun’s rays make dry grasses burst into flames. Man probably discovered by accident that fire could actually be made. Perhaps he took a burning stick from a forest fire and kept the flames going by adding more sticks or maybe be, those early tool-makers noticed that the rocks they chipped sent out sparks that could start fires. In any case, Man discovered that fire could completely change his way of life. Early man made fire either by striking stones, or by rubbing pieces of wood together.

The discovery of fire had many far reaching consequences. So, it is considered as the single most important discovery made Man superior to animals.