Life expectancy is the average number of years a person is expected to live based on statistical data. It is influenced by various factors, including genetics, lifestyle, healthcare access, and environmental conditions. Countries with better healthcare systems and healthier lifestyles typically have higher life expectancies. This measure can vary significantly between different regions and populations. For example, developed countries often report higher life expectancies than developing countries. Additionally, life expectancy can differ based on gender, with women generally living longer than men in many parts of the world.