Entropy:A measure of disorder or randomness in a system. If we scatter all coins and bills from your piggy bank on your bed, entropy increases because there’s more disorder now!
Gibbs Free Energy:Represents available energy to do work at constant temperature and pressure. It's like counting only those coins from your piggy bank which are not pennies – this gives you real spending power!
Internal Energy:The total kinetic and potential energies associated with random motion of molecules within a system; it's like the total amount of coins and bills in your piggy bank.