Composites are a class of materials manufactured from more than one type of raw product. A typical example would be that of synthetic fibers set within a resin as in the case of glass-reinforced plastic (GRP, or "fiberglass") or an aramid-based material (such as Du Pont's Kevlar).
Composites are increasingly widely used in the automotive, marine and aerospace industries. In the latter case they were vital in developing stealthy aircraft, where composites replace metals to reduce radar reflections. Composites came about due to great advances in plastics and recycling. They allow engineers the option of replacing heavy metal components with lightweight composite ones of the same strength. They have also replaced many non-metallic materials such as wood, where they offer much greater strength for the same low weight.