A Simple Definition: "A combination of two or more materials (reinforcing elements, fillers, and composite matrix binder), differing in form or composition on a macroscale. The constituents retain their identities. Normally, the components can be physically identified and exhibit an interface between one another.  The properties are usually superior and possibly unique to the properties of the individual component."
Composite materials have different properties in different directions.  You can manufacture composites suitable to specific applications, and this basic ability to manipulate their properties makes them very attractive for several applications.

Basic Properties: "Light weight, non-corrosive, non-conductive, anisotropy, ........ ."

Types of Composites:   "Polymer Matrix Composites,
                                    Metal Matrix Composites,
                                    Ceramic Matrix Composites,
                                    Carbon Matrix Composites."
Some Applications of Composites:
 
    Aerospace
    Automotive
    Sporting Goods
    Marine
    Electronics
    Civil Construction
 
 

Real life applications: