A king bed is a large mattress size that measures 76 inches wide by 80 inches long. It provides ample space for couples or individuals who enjoy extra room while sleeping. King beds are ideal for spacious bedrooms and are often chosen for their comfort and luxury. There are different types of king beds, including the California king, which is slightly narrower and longer at 72 inches wide and 84 inches long. King beds typically require larger bed frames and bedding, making them a popular choice for those who prioritize a comfortable sleeping experience.