Equilibrium:In a reversible reaction at equilibrium, the rates of the forward and reverse reactions are equal, resulting in no net change in concentrations of reactants or products.
Le Chatelier's Principle: This principle states that if a system at equilibrium is disturbed by changes in temperature, pressure or concentration of reactants/products, it will respond by shifting in such a way as to minimize those changes.
Irreversible Reaction: Unlike reversible reactions, irreversible reactions proceed only from reactants to products and cannot easily return to their original state.