Pocket springs are individual coils used in mattresses that provide support and comfort. Each spring is encased in its own fabric pocket, allowing them to move independently. This design helps to reduce motion transfer, meaning that if one person moves, the other is less likely to feel it. These springs adapt to the body's shape, offering targeted support to different areas, such as the lower back and shoulders. Pocket spring mattresses are popular for their durability and ability to maintain their shape over time, making them a favored choice for many sleepers.