Define Buffers and Buffer Solutions?

Solutions containing both weak acid and their salts or solutions containing weak hydroxides and their salts are referred to as buffer solutions. They have the capacity of resisting changes in pH when either acid or alkali is added to them. Buffers are therefore, aqueous solutions that tend to resist any pH change when small amounts of acid or base are added. A buffer system consists of a weak acid (proton donor) and its conjugate base (proton acceptor) or a weak base and its conjugate acid in comparable concentrations. Because they maintain a constant pH, buffers are good reference solutions.