From Ekopedia

[edit] What is a Cloth diaper ?

A cloth diaper is a diaper formed like a disposable one, except that you can wash it instead of adding it to landfills. For more absorption and according to models, you can add a double-layer inside (very useful for the nights). Cloth diapers are reusable and can be made from natural fibers, man-made materials, or a combination of both. They are often made from cotton which may be bleached white or left a natural color. Other natural materials (often grown without pesticides), such as wool, bamboo, unbleached hemp, are also used. Man made materials such as microfiber toweling (for absorbency), or PUL aka polyurethane laminate (for a waterproof layer) may be used. Another popular non-natural fiber is polyester fleece and faux suedecloth, used inside cloth diapers as a "stay-dry" wicking liner, because of the non-absorbent properties of synthetic fibers. Elastic is also commonly used.

An estimated 27.4 billion disposable diapers are used each year in the US, resulting in a possible 3.4 million tons of used diapers adding to landfills each year.

See also Cloth diaper.