Biological age refers to the age of an individual based on biological and physiological markers rather than chronological age. It considers factors such as genetics, lifestyle, and health conditions to assess how well a person's body is functioning compared to others of the same chronological age. This concept is often measured through various tests that evaluate aspects like metabolism, cellular health, and organ function. Understanding biological age can help identify potential health risks and guide personalized health interventions, promoting better overall well-being and longevity.