Question

How does a heat form?

Answer 1

The Universe is made up of matter and energy. Matter is made up of atoms and molecules (groupings of atoms) and energy causes the atoms and molecules to always be in motion - either bumping into each other or vibrating back and forth. The motion of atoms and molecules creates a form of energy called heat or thermal energy which is present in all matter.
that mean motion of atom and molecules is reason behind heat formation when they travel they have collison with each other and transfer heat as well