Life expectancy is a measure of how long a person is expected to live, based on statistical averages. It takes into account various factors such as health, lifestyle, and access to medical care. For example, people in countries with advanced healthcare systems, like Japan or Sweden, often have higher life expectancies compared to those in developing nations. Several factors can influence life expectancy, including diet, exercise, and genetics. For instance, individuals who maintain a balanced diet and engage in regular physical activity tend to live longer, healthier lives. Additionally, advancements in medicine, such as vaccines and treatments for diseases, have significantly increased life expectancy over the years.