As a system approaches equilibrium, the rates of the forward and backward reactions change. Initially, the rate of the forward reaction is higher because reactants are being converted into products. Over time, as the concentration of the products increases and the concentration of the reactants decreases, the rate of the forward reaction slows down. Simultaneously, the rate of the backward reaction (where products are converted back into reactants) starts off slower but gradually increases as the concentration of products increases. Eventually, when the rates of the forward and backward reactions become equal, the system reaches equilibrium, and there is no net change in the concentrations of reactants and products.