the.com/bare bones

means The basic, minimal version of something — stripped down to only its essential parts, with nothing extra added.

from A straightforward image: strip away the flesh, skin, and fat from a body, and what remains — the bare bones — is the skeleton, the literal minimum structure holding the thing together. The phrase has been used figuratively since at least the 19th century for anything reduced to its essentials, long before it got borrowed into business-speak for budgets and project plans stripped of every frill.