Blue stragglers are celestial misfits. They stand out from the crowd, and they require special explanation. Remarkably, for so the observations indicate, they have aged differently to similar mass 'normal' stars. First recognized as being altogether different in the early 1950s, blue stragglers have occupied the thoughts of astronomers ever since. This book looks into the mystery of blue straggler origins, and offers its readers an insight in to how astronomers measure and determine the properties of stars in general. Indeed, the book will take the reader through the basic physics and geometry that is needed to understand the essential observations and theory of stars and star clusters.