The law of conservation of energy states that energy can neither be created nor destroyed. What does “conservation” mean in this law? I need the answer quickly

Conservation means to improve something to prevent loss or decay
That's why energy can't be created or destroyed

In physics and chemistry, 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.

Conservation used in this sense i would think would be referring to the act
the principle by which the total value of a physical quantity or parameter (such as energy, mass, linear or angular momentum) remains constant in a system which is not subject to external influence.