A cap is a flat headgear, usually with a visor. Caps have crowns that fit very close to the head. They made their first appearance as early as 3200 BC. Caps typically have a visor, or no brim at all. They are popular in casual and informal settings, and are seen in sports and fashion. They are typically designed for warmth, and often incorporate a visor to block sunlight from the eyes. They come in many shapes, sizes, and are of different brands. Baseball caps are one of the most common types of cap.