Answer:
Is a substance that can maintain certain range of pH
Step-by-step explanation:
A buffer is mixture of two salts that are complementary, one salt is acid and another is basic, but since then share some part of their structure, if you add to this mixture another acid, the basic salt can absorb it and still maintaining the same pH. If you pour a base, the acid salt will absorb it and again the final pH will remain the same. So the buffers are used to maintain the same pH does not matter if you add small quantities of an acid or base.