which energy can be defined Energy transformation, relating to energy's changes from one form to another. Energy (signal processing), the inner product of a signal in the time domain Energy density spectrum, relating to the distribution of signal energy over frequencies. Potential energy, the form of energy that is due to position of an object Kinetic energy, the form of energy as a consequence of the motion of an object or its constituents Mechanical energy, the potential energy and kinetic energy present in the components of a mechanical system Binding energy, a concept explaining how the constituents of atoms or molecules are bound together Bond energy, a measure of the strength of a chemical bond Nuclear energy, energy that is the consequence of decomposition or combination of atomic nuclei Osmotic power, also salinity gradient power or blue energy, the energy available from the difference in the salt concentration between seawater and river water Gibbs free energy, a related concept in chemical thermodynamics that incorporates entropy considerations Helmholtz free energy, a thermodynamic potential that measures the "useful" work obtainable from a closed thermodynamic system at a constant temperature, useful for studying explosive chemical reactions Elastic energy, which causes or is released by the elastic distortion of a solid or a fluid Ionization energy (IE), the energy required to strip an atom of an electron Interaction energy, the contribution to the total energy that is a result of interaction between the objects being considered Internal energy (abbreviated E or U), the total kinetic energy due to the motion of molecules (translational, rotational, vibrational) and the total potential energy associated with the vibrational and electric energy of atoms within molecules. Negative energy Energy conversion, process of converting energy from one form to another Dark energy, used to explain some cosmological phenomena Energy quality, empirical experience of the characteristics of different energy forms as they flow and transform Energy density, amount of energy stored in a given system or region of space per unit volume, or per unit mass Energy flow, flow of energy in an ecosystem through food chains Energetics (disambiguation), the scientific study of energy in general Stress–energy tensor, the density and flux of energy and momentum in space-time; the source of the gravitational field in general relativity Food energy, energy in food that is available Primary energy, energy contained in raw fuels and any other forms of energy received by a