There's a difference between a cm being the thing that exists between the lines with 0 and 1 against them and the distance that is 1cm. Indexing is within the

There's a difference between a cm being the thing that exists between the lines with 0 and 1 against them and the distance that is 1cm. Indexing is within the scope of the first definition. You might as well ask where the 0 or 1th element in an array starts and finishes.