For the purposes of this article, composite materials are those in which fibers, or some type of linear structures, are bound tightly in a solid matrix, such as plastic or concrete. The matrix material, while having its own strength and structural characteristics, serves primarily to hold the fibers or reinforcing structures in place.

Man's first use of such composite materials was probably the adobe brick. Mud or clay can be shaped and dried into a hard block, but that kind of block has little load bearing strength and can be easily crushed by the weight of other blocks on top of it. At some point in time, Man found that mixing dried grass or straw into the mud produced a brick with superior properties; a brick that could bear much greater loads without being crushed than a brick of plain dried mud could bear. Thus was born the ability to construct large, secure buildings that were the foundation of cities and of society. Adobe bricks are still in common use in many areas of the world today, essentially unmodified after thousands of years.

Plywood is another example of Man's attempts to capture and employ Nature's inherent wisdom. In plywood, thin sheets, or 'plies' of wood are laminated together. In each ply, the wood fibers (the grain of the wood) runs in one particular direction, and each ply is aligned in a different direction than the adjacent plies. This gives the resulting stack of wood plies an optimum strength in all directions, and plywood is a very versatile and useful structural material.

Another example of a composite material is reinforced concrete, as is used in the construction of bridges and buildings. Steel rods ("rebar", short for "reinforcing bars") are encased in a matrix of concrete, producing reinforced concrete, which has much better strength and load-bearing properties than concrete that has not been reinforced. Curiously, the load-bearing capacity of reinforced concrete lies in the steel rods that it contains, and not in the concrete itself. We think of the steel rods as reinforcing the concrete, when in fact the reverse is true. While the concrete itself is strong, its actual purpose is to hold the steel rods in place. The steel rods bear the load, and the concrete actually reinforces the steel rods!

As interesting as they are, these materials - bricks, plywood, reinforced concrete - are not advanced composite materials. Though the operating principles of the materials are the same, airplanes and other such structures are generally not built from artificial stone and plywood.