There are a range of different bed sizes available for different sized people and sleeping preferences. The smallest bed sizes include twin and full bed sizes. These beds are meant for sleeping single people but it is possible to squeeze more than one person into the bed if they are children. The twin size is the smallest and most suitable for children. The size that is most comfortable for sleeping one person of an older age is the full size. Most adult people can comfortably sleep alone in a full size without feeling cramped. The next larger bed size following the twin and full size is the queen sized bed. The queen sized bed is great for someone who likes to spread out in their sleep, roll over and move around. This bed has plenty of space and is also great for couples who share a bed together. There is plenty of room for two people to sleep comfortably on a queen sized bed. For those who prefer to feel as if they are sleeping in a grand amount of space, a king sized mattress is the next size up. Following the king size is the even larger California king.