Some of the top beds and mattresses around in the modern world use memory foam. Examples of brands that include this technology include Tempurpedic and knockoffs like “Bobopedic.” This technology was first created by NASA to help create safer conditions for astronauts by incorporating it into cushions on airplanes in the 60s. It was initially called “slow spring back foam,” but eventually got the term “memory foam” because anyone pressing into the foam could see the imprint of their fingers for a while afterwards.
The foam is used in top beds because it naturally molds itself to the body of anyone lying in it. While it’s true that there are other ways to make use of memory foam, such as putting a thin wedge of it on top of a more traditional spring bed, the beds that use memory foam throughout often tend to be the most comfortable by far.
Traditional spring beds aren’t as good at perfectly molding around your body. They also have springs which eventually give out and sag, which memory foam doesn’t have nearly as much of a problem with. Pocket spring mattresses can also have the disadvantage of having dangerous metal springs poking out from underneath the mattress if they become damaged.
Memory foam also has great isolation, meaning you can actually put a wine glass on one side of the bed, and then stand up on the other and the interaction between sides will be minimal. This isn’t possible on a spring mattress, since the springs all interconnect. This is beneficial since two people can sleep on the same memory foam bed without disturbing each other like they often do when they’re both sleeping on a spring mattress.