Delta S (∆S): This is the change in entropy during a reaction. Using our analogy, if you scatter some coins on your bed from your piggy bank, ∆S would be positive because disorder increased.
Delta G (∆G): This is the change in Gibbs free energy during a reaction. If we consider only those coins which are not pennies for spending, any increase or decrease while buying things would represent ∆G.
Heat Capacity:The amount of heat required to raise the temperature of a substance by one degree Celsius. In terms of our analogy, it's like how many coins you need to add into your piggy bank to buy an ice cream that costs one dollar more than yesterday.