No, the term "miles" comes from the fact that you (used to at some some airlines, still do at others) earn about 1 mile for every mile flown.

But obviously airlines don't want to give you one free for every one paid. So it takes way more miles to redeem for a given flight than you earn if fly that same flight paid.

Typically it's a minimum of 25000 miles for a domestic USA round-trip (not counting Hawaii but counting Alaska) in "controlled capacity" coach (ie, far from every flight being available at that level), and minimum of 40000 for overseas round-trip flights beyond Hawaii in "controlled capacity" coach. (And that 40000 amount is just off-peak to certain destinations, 50000 is a more common minimum.) Business or first class is typically at least double that. And "last seat" awards are typically double to triple either of those.

(FYI: The "controlled capcity" awards are often referred to as "saver" awards, and the "last seat" awards are often referred to as "anytime" awards.)