Did you know that a boomer is a person between the age of 55 and 75?
If you are a millennial, your parents are probably boomers - which is short for baby boomers.
They belong to a huge generation of people born between 1945 and 1965, right after the second world war.
Today, younger generations use the phrase "ok, boomer" to express their skepticism or dissatisfaction with how this older generation thinks - and how they've handled issues like climate change.