In Physics, energy is a quantitative property that must be transferred to an object in order for it to perform work. Hence, we can define energy as the strength to do any kind of physical activity. Thus, they say,

ENERGY IS THE ABILITY TO DO WORK.

I hope my answer helps. All the very best for your future endeavors!

Dear student,

In physics energy the capacity for doing work or it is a form of work.
Energy can be in potential, kinetic, thermal, electrical, chemical, nuclear, or other various forms.

Energy can neither be created nor be destroyed,energycan only be transferred from one body to another. And this is called law of conservation of energy. Heat and work is also a form of energy.