This is exactly the kind of distinction a directory branch handles well. Readers often arrive with the words biological age and biological aging treated as interchangeable, even though one is an estimate and the other is the ongoing process that scientists are trying to model.
Keeping this as a dedicated topic entry creates room to expand later into subtopics like epigenetic clocks, rate of aging, and why different tests disagree. The article handles the explanation in full. The glossary keeps the shorter definition tight. The directory entry sits between them as the durable topic map.
Educational content: This page covers ongoing scientific research. Evidence levels vary. Nothing here is medical advice. Consult qualified medical professionals before making health decisions.