Carbon is a composite material, which consists of carbon fibers fixed with epoxy resins.
The main component of carbon is carbon fiber. These fibers are very thin, they are very easy to break, but it is quite difficult to tear them. Carbon fabrics are made of these fibers. Carbon fabrics have a different weave pattern (herringbone, matting and so on.). For extra strength the fabrics are interleaved. The layers are bonded with epoxy resins.
Carbon has its advantages and disadvantages. The main advantages are strength and light weight. Carbon is as straight as most metals, but in weight carbon is 40% lighter than steel and 20% lighter than aluminum. Moreover, carbon parts are stronger than fiberglass parts. That is why carbon is so widely used.
Now about the disadvantages. The cost of carbon parts is much higher than the cost of the same parts made of fiberglass. The high cost of carbon is connected with more complicated technology of production and more expensive materials. For example, for layers’ bonding are used more expensive resins, than for fiberglass, and the technology of production requires more expensive equipment, for example, an autoclave.