I agree with @johnpowell there are three types of averages commonly used, mean, mode, and median.
Mean is when you add everything up and divide by how many numbers were given.
Mode is the number that most commonly occurs.
Median is the number in the middle.
It is important to know the difference because when averages are given sometimes the answer can vary greatly from one type of average to another, so it can be deceptive. It is always good to ask how an average was reached, by mean, mode, or median. Things like housing prices are generally given in median averages. I think life expectancy they use mean. Many things we hear quoted every day, we don’t necessarily pay attention to what type of average they are using. Take the statement that people only lived an average of 40 years a 100 years ago (I don’t know the real number, I am guessing more or less) since there was a lot of infant mortality, that could mean a lot of people died before the age of 1, and then many also made it to the age of 80. It does not have to mean that the majority of the people died at age 40. But if 40 is the mode, then yes most died at that age.