Kevlar is a synthetic material known as a polymer (aren't you glad you asked?). A Kevlar fiber is an array of molecules that are paralllel to each other like spaghetti in a package. These chains are held together by electrostatic forces between molecules known as hydrogen bonds. The fibers are drawn at a temperature over 750 degrees Fahrenheit. (If you must know, the actual chemical name of Kevlar is poly-para-phenylene terephthalamide, but we didn't tell you.)
All this chemistry stuff leads to a material 5 times stronger per weight than steel and about half the density of fiberglass.
It was a lady named Stephanie Louise Kwolek who pioneered the research leading to the marketing of Kevlar by Dupont in the mid-70's.
General features of Kevlar include:
Kevlar has been layered into bullet-resistant vests, but is also used in belts for radial tires, cables (used on the Mars Pathfinder), reinforced composites for aircraft panels and boat hulls, flame-resistant garments (especially in blends with Nomex), sports equipment such as golf club shafts and lightweight bicycles, as asbestos replacements in clutches and brakes, and in Welding Jackets, Work Gloves, and Work Boots. Our last bit of information is that you always double check that the products you buy for the previous features and benefits are actually made with Kevlar. If you just assume they are, you may make a dangerous mistake by leaving yourself exposed to hazardous situations.