A buffer is a solution that resists changes in pH when small amounts of an acid or base are added. It typically consists of a weak acid and its conjugate base, or a weak base and its conjugate acid. This property makes buffers essential in many biological and chemical processes, as they help maintain stable conditions. In everyday life, buffers are important in various applications, such as in the human body, where blood contains buffers to regulate pH levels. They are also used in laboratory settings to ensure accurate results in experiments involving enzymes and other sensitive reactions.