From agricultural soils to the clouds and fogs which influence our weather; from cosmetics to pharmaceuticals; from the food we eat to the structure of biological cells - most of the materials around us are made up of colloids. Colloidal systems are also important in the paper, paint and ink industries, either in the final products or at crucial stages in their manufacture. This book provides an introduction to the area of science which seeks to understand those processes which govern the behaviour of these systems. The emphasis is on providing a sound basic understanding on which later, more advanced study can be built. The book offers a gentle introduction to the author's two-volume reference book Foundations of Colloid Science, which can be used to take the specialist reader into the latest research literature.