Charcoal is made by heating wood (usually Willow or Grape Vine) in a kiln to remove the moisture content which carbonises the wood. This brittle carbonised wood (charcoal) can be used for drawing and sketching.
Compressed charcoal is made from powdered charcoal combined with a binding agent to form stronger sticks that are less likely to break. Lines are usually darker and the sticks can be used on their side to create broad strokes.
Charcoal pencils are made using charcoal particles and fine clays. The pencils offer a little more control in charcoal drawings because the charcoal can be sharpened using a pencil sharpener and are slightly less messy than traditional charcoals. The tinted charcoals include a small amount of coloured pigment to add a further dimension to sketches.