تعریف و معنای "it [is] six of one, half a dozen of the other"

What is the origin of the idiom "it is six of one, half a dozen of the other" and when to use it?

The idiom "it is six of one, half a dozen of the other" is derived from the mathematical equivalence between the numbers six and half a dozen, which both represent the quantity of twelve. The phrase is used to convey the idea that two options or choices being considered are essentially the same or result in an equal outcome.