Arrows are these weird little things that can impale themselves in your knee. They were first used by the Ancient Geeks before they used guns. Arrows can serve a variety of purposes, even picking one's nose (not recommended)! The arrow is not as popular today as it once was, but it's still used by Robin Hood because he can't accept that guns are cool.
The arrow was first invented on September 2nd by Thomas Edison in the days before they invented calendars. When he invented them, Ysgramor adopted the arrow as the official currency of Skyrim. The arrows were invented to function as weapons, but YOLO. This presented a problem throughout Skyrim's history as people kept getting hit by arrows in the knee.