A more quantitative view of energy Kinetic energy relates to the mass and velocity of a moving object. Something weighing 2 kilograms would have twice the kinetic energy of a 1 kilogram object if they were moving at the same velocity. The kinetic energy of a system is the sum of the kinetic energy of each body. Air particles, for example, move randomly and each has its own kinetic energy. If you sum the kinetic energy of each particle and take the average, that average is the temperature .
Heat is a combination of temperature and the number of particles.
We're most interested in gravitational and mass-energy. Gravitational potential energy governs how a body falls to the ground, motion of the planets, formation of solar systems and galaxies, etc. A ball's potential energy is greater if it's perched on top of the building compared to if it's sitting on the table. With the collapsing pre-Sun gas cloud, as it collapsed and converted its PE to KE, the gas heated up so it could become hot enough to start nuclear reactions. Einstein showed that matter and energy could be interchanged and that in fact mass-energy is conserved.