A 2 in 1 mattress is a mattress that has 2 benefits in one mattress. In other words, a 2 in 1 mattress means you can get two mattresses as a pair in a single purchase. This mattress model usually grows upwards, not sideways, and has a compact shape. Therefore, it is no surprise that this mattress model is a popular choice for many people to manage limited room space. This mattress is very suitable if you share a room with your roommate but still want to have your own mattress so that your movement space is free.