A device for making marks for the purposes of communication (writing), held in the hand. In a modern sense, it usually accomplished by moving ink from the writing instrument to paper (or a bathroom wall, or a desk, or, in a pinch, a hand). Prior to that (and, oddly enough, more recently), a writing instrument would have no ink, but either make marks in a clay tablet (ancient), or trigger a computer to display characters (modern).

Writing Instruments include:

Though this is not an exhaustive list.