The "average life expectancy" is the average age that people live until. You can find out the "average life expectancy" for a country or region, or an overall average life expectancy for the world:

The average life expectancy for a baby born in South Korea today is over 80 years!

If the life expectancy for a country is 70 years, that means that some people will die when they are much younger than 70, but many people will live to be older than 70 as well.