From birth till the long process of growth, children are In a constant transitional state from one to another. As for the very initial stage, a very common problem in the past was that the kids fell down the bed while no one was around them. For this very reason concept of crib bedding was introduced, which provided a little wall or grill around the bed preventing the baby from falling down.
At first it was only a boring simple bed with walls, but soon developed into attractive structures that besides providing protection from falling, also provided entertainment for infants. Toys, hanging down from the top is a good way of keeping children busy.
Especially in U.S it is a common trend to let little infants have a room of their own and be alone in their room for hours. In such case it would not be acceptable if the kids kept on falling and hurting themselves. Crib bedding is now used on a massive scale around the globe.
They can be further developed and improved in many ways. Putting stickers on the roof will be another way of keeping the babies busy, allowing you to enjoy peace for long. Also pasting informative or knowledgeable diagrams on walls of the bed will let infants enter the stage of learning and get them used to the necessary process.
Further developing their minds and contributing to their growth will be another consequence. The Bed could be made safer by adding a higher layer of wall, foamed to avoid harm from edges.