Energy - thermodynamics:
The energy can be defined as the capacity of doing work. The energy possessed by system may be of two kinds.
1. Stored energy: for example potential, internal, kinetic energy etc.
2. Transit energy: for example heat, work, flow energy etc.
The stored energy is that which is contained within system boundaries, but the transit energy crosses system boundary. The store energy is thermodynamic property whereas the transit energy is not thermodynamic property as it depends upon path.
For instance, the kinetic energy of steam issuing out from the steam nozzle and impinging upon steam turbine blade is an example of stored energy. Likewise, the heat energy produced in combustion chamber of gas turbine is transferred beyond the chamber by conduction or convection and radiation, is an example of transit energy.