A mattress is the thick, cushioned pad you sleep on top of your bed frame. Mattresses are designed to support your body comfortably through the night, filled with materials like foam, springs, or air. A good mattress keeps your spine aligned while you sleep, which is why people spend so much time choosing the right one.

Before mattresses, people slept on much simpler surfaces: straw, animal skins, or simple cloth sacks stuffed with whatever soft material they could find. Medieval Europeans learned about mattresses from Middle Eastern traders and gradually improved the design. By the 1800s, inventors had created spring mattresses, and by the 1900s, foam and other materials made mattresses even more comfortable.

Today's mattresses come in many types. Some use metal coils that compress and bounce back. Others use memory foam that molds to your body shape. Some even have air chambers that inflate or deflate to adjust firmness. When you go mattress shopping with your parents, you'll notice how different each one feels, because finding the right mattress matters: you spend about a third of your life sleeping on one.