Innerspring mattresses are one of the most common types for their affordability and durability. These mattresses, as their name suggests, are made up of several coiled springs cushioned between layers of fabric, the number of which can range from several hundred to a thousand, depending on the mattress' size. The thickness of the coiled wires used will often determine the firmness of the mattress.
Foam mattresses were introduced in the 1970s and have since become favorites thanks to their ability to conform to a body shape, allowing sleepers to "sink" comfortably into their mattresses. Foam mattresses can be far more expensive than innerspring mattresses, making them less common. They often feature a type of foam branded "memory foam" or latex.
Futon mattresses are usually on the lower end of the mattress spectrum and are used for futons, which are pieces of furniture that can switch between a lounger and a bed. Though they can be made with springs or foam, most futon mattresses are simply filled with cotton, giving them flexibility so that they can be folded easily. They are typically much thinner than standard mattresses to accommodate their increased flexibility.
Air mattresses are designed to be temporary. They are usually made of latex and can be inflated into overnight mattresses, then deflated in the morning for easy storage. They may be common when visiting relatives or friends and sometimes come with built-in electronic pumps for easy inflation and deflation. They are typically available from twin to queen sizes.
Water beds are not as firm as other types of mattresses and consist of sacks of water. The water can be heated, making water beds therapeutic to some. However, they can be squishy, which can be uncomfortable, or can potentially leak. Firmer water beds use wooden frames to put water under pressure while softer water beds use a cloth or foam casing.