A pillow-top mattress is a type of mattress that features an additional layer of cushioning sewn onto the top. This layer is typically made from materials like foam, latex, or fiber, providing extra softness and comfort. Pillow-tops are designed to enhance the sleeping experience by offering a plush surface that can help relieve pressure points. These mattresses come in various styles, including innerspring, memory foam, and hybrid options. The added cushioning can make them suitable for side sleepers who need more support for their hips and shoulders. However, they may require more maintenance and can be heavier than standard mattresses.