What does it means to say that energy is conserved in an energy transformation?

The law of conservation of energy states that the total energy of an isolated system remains constant , it Is said to be conserved over time. This law means that energy neither be created nor destroyed ;Rather, it can only be transformed or transferred from one form to another form  

If I put a battery (chemical potential energy) and wire it to a resistor, a light bulb, and a solenoid, I will get a transfer of the chemical potential energy (which is manifested as a electromagnetic voltage potential when the wires are connected) to electromagnetic (heat from resistor and light and heat from bulb) and kinetic (solenoid bounces) energy. If I lifted something with an engine hoist, I changed electromagnetic energy into gravitational potential energy.