For you have not received the spirit of bondage again to fear; but you have received the Spirit of adoption, whereby we cry, Abba, Father. For ye received not the spirit of bondage again unto fear; but ye received the spirit of adoption, whereby we cry, Abba, Father.
Hence, entropy can be understood as a measure of molecular disorder within a macroscopic system. The second law of thermodynamics states that an isolated system's entropy never decreases. Such systems spontaneously evolve towards thermodynamic equilibrium, the state with maximum entropy.
Entropy is a state function. In order to understand the relationship between change in entropy and heat, we need to remember that heat is not a state function. Suppose a system undergoes a process in which it changes from an initial state (State 1) to a final state (State 2).