Width is how far something extends from side to side. When you measure the width of your desk, you're finding the distance from its left edge to its right edge. A hallway might be five feet in width, meaning five feet across. A river's width tells you how far you'd have to swim or build a bridge to get from one bank to the other.

Width is one of the three basic dimensions we use to describe objects, along with length (how long something is from end to end) and height (how tall it is from bottom to top). Picture a swimming pool: its length runs from the shallow end to the deep end, its width measures across from lane to lane, and its height (or depth) goes from the surface down to the bottom.

People often confuse width and length, but here's a simple way to think about it: length usually refers to the longest dimension of something, while width typically describes a shorter side-to-side measurement. A football field's length runs 100 yards between the end zones, while its width spans about 53 yards across. When you describe something as wide, you're talking about its width: a wide river is hard to cross, while a narrow stream might let you hop across on stones.