A monocoque is a structural system where loads are supported through an object's external skin like an eggshell. It originated in motorcycle racing in the 1960s when Ossa developed a monocoque frame that was lighter and stiffer. Other notable early uses include Norton's 1973 Isle of Man TT winning bike and John Britten's 1987 Aero-D One. Monocoque frames provide benefits like weight savings, compact designs, and rigidity over perimeter frames but are more complex and expensive to produce.