Energy itself is the property in physics of objects which could be transferred to or converted into other forms. The main description of energy is the ability of the system to do work but it might be difficult to give single words to define energy. The energy has SI unit which is joule and one single joule is equal to the energy which is transferred to an object by doing some mechanical work or just moving it 1m against the force i.e. 1 newton. But there are many definitions of different forms of energy including thermal, electromagnetic, radiant, and nuclear and this definition are more convenient to define energy.
The energy has many forms and the whole energy could be also sub divided into several ways. The energy in the form of nuclear energy could be used in nuclear reactor or atomic power plants. It helps out in forming electricity with low cost. The forms of energy heat through which energy could be gained and more electricity is produced by this principle. The energy is defined in all different field in an own way likely the energy in medical field related to human and this energy is gained by in taking of food i.e. healthy meal and in chemistry it is and an attribute of an element as the consequence of its aggregate structure & atomic structure.
Energy gave rise to weight when it enacted a system with no momentum where it could be weighted. It is equal to the mass of the body and the mass is linked with it and the mass itself is equal to the some amount of energy and the famous physician Albert Einstein in 1905 described his view about energy-mass equation equivalence. The matter might convert its form to energy but mass cannot be destroyed and they remain constant throughout any process and when they changed their shape to each other. Now came to another point about thermodynamics in which energy divided into two kinds with two processes reversible & irreversible and in a reversible process the energy is whole dissipated and could not be recovered. In a reversible process in which the dissipation does not happen. According to the law of conservation of energy, the energy is the one which couldn’t be created nor be destroyed but it can be changed its form to another form. The simple definition is the total incoming flow is equal to total out coming flow & with the changed in energy reserved in the system. The energy in the form of heat is used for generating electricity. The heat gives stream and then this stream helped in running the turbine & the heat engines which are made to convert this heat into light. The sunlight energy which is also for doing some purposes because when light from the sun falls on the solar plates which are made such like that they heat up & from it the energy from wire goes from wire to transformer in this way the high amount of energy could be produced from it. The human body also used energy during mechanical work because the energy is being used during the workout and that energy used is gained by food fulfilled with proteins etc. The mechanical energy is the mixed form of both kinetic & potential energy in a system.
The energy is measured as positive or negative according to their dependence upon that might they are greater or smaller and the physicists are recently working on this energy. The difference between these forms of energy is not very clear. That notion of potential and kinetic energy stands on the notion of length scale. If one could speak about potential & kinetic energy which does not include these above-mentioned energy. The thermodynamics also includes the internal energy, this energy is the mixture of all kinds of form of the energy system and this energy is required to create the whole system and it is relevant to the potential energy. This is also concerned with the few changes in internal energy which is not exactly the absolute value and it is impossible to conclude energy without thermodynamics. In international system of units, energy has a specific unit called joule and it is also be expressed in different units like the thermal unit, calories which are required factor when it is defined in SI units. Energy produced from the dam of water is used for domestic purposes. The water is the cheaper source of producing electricity and the water when falls on the blades of turbine convert it into electric form through an electrical generator which is connected to it. This is from heat to work and this energy is applicable in our daily life for also other purposes. Because energy could be transformed into various format specific efficiency that transforms these form and the battery carries out this work.