A substance that reacts with hydrogen or hydroxyl ions in a solution, in order to prevent a change in pH. Buffers are also capable of being impervious to pH change with the incorporation of basic or acidic compounds. They are used to quell these compounds when found in low degree in order to keep the pH of the solution stabilized. Buffers provide this important need for processes that necessitate particular and well balanced pH ranges. The capacity and working pH range of the bugger will also influence the quantity of acid/base of which can be neutralized before the pH alters.