Used by artists since the Renaissance, pastels are an art medium in the form of a stick, consisting of pure powdered pigment and a binder. The pigments are the same as those in other media, including oil and watercolour paints.
I love pastels because of the colours and effects they produce and because you work them directly on the paper with your fingers, not a brush; you really are at one with the painting. Also, you don't have to worry about mixing, washes, drying times, thinners, layering and all the other things you have to think about with other media.
Pastels are sometimes described as the most permanent of all art media. They don't contain the chemicals and binders used in oil paints, meaning that they won't crack or darken with age. Degas, Cassatt, Manet and Toulouse-Lautrec were all profuse users of pastels and their paintings look as good and fresh today as they did when they created them.
You can watch me using pastels here.