This refers to the amount of acid or base that can be added to a buffer without causing a significant change in pH.
Acidic Buffer: An acidic buffer is a type of buffer made from a weak acid and its salt (which will be composed of its conjugate base and a cation). It has a pH less than 7.
Basic Buffer: A basic buffer is made from a weak base and its salt (which will be composed of its conjugate acid and an anion). It has a pH greater than 7.