Experimental and evolutionary perspectives are converging in the current science of aging and longevity, attempting to unify significant findings from different areas of biology. Aging is a complex, multifactorial process of molecular and cellular decline that over time affects tissue function, making organisms frail and susceptible to disease and death. Different lines of research are illuminating avenues for discovering anti-aging interventions that can be applied to humans as well. In this review we considered what exactly and how affects life expectancy, what are the mechanisms of aging and is there a possibility of life extension. А major challenge for unraveling the topic is a complete understanding of the molecular, cellular, biochemical, genetic, and epigenetic mechanisms underlying age-related deterioration and repair, how these pathways are interconnected and what slows human aging while increasing molecular and physiological youth, vitality and health. In this review, we review and summarize key theories underlying the biology of healthy aging and active longevity.