Nothing is quite so liberating for an artist - or aspiring artist - than a good light, several large sheets of medium textured drawing stock, and a handful of soft, ‘moderately black’ charcoal sticks.  There is something natural, basic, and elementary about working with charcoal.  
Perhaps when one of our caveman ancestors first pulled a lump of charcoal from the communal fire pit and drew the first charcoal drawing on a cave wall, he (or she) triggered a gnome mutation that has vibrated down through the centuries into the present.  
Other media - oils, pastels, acrylics, watercolors, etc. - have all changed over the centuries, but charcoal has remained simply charcoal, an impure form of elemental carbon that results from burning woods in low-oxygen conditions.  How could we not be all naturally drawn to this artist’s tool?
Charcoal as a medium is fast, direct, and responsive.  It’s with very good reason that beginning art students are encouraged to sketch with charcoal to practice line flow, contours, shading, light and shadow, and emphasis.  Bold and frequent application of charcoal is the best way for a new artist to find his or her personal technique and unique style.
Charcoal it is one of the least inhibiting of drawing media. It can be used to produce bold and fluid lines, a wide range of textures, and achieve subtle shadings as well.
All three of the basic drawing techniques can be practiced using charcoal:  contour drawing, gestural drawing, and volume drawing.
Contour drawing, or drawing outlines of varying thickness to define a subject and express shadow and strength.  This has its painting equivalent in Chinese ink brush drawings.
Gestural drawing, or ‘scribble’ drawings to express motion or emotion, the most painterly approach and a good warm up for working in pastels or oils.
Volume drawing, with consists almost entirely of shading to produce a chiaroscuro effect, applying no lines except perhaps when a cross-hatch technique is used to show texture.  This is an excellent warm up to watercolor painting.
Probably due to its availability, versatility and low cost, charcoal became the common practice medium used throughout the ages and throughout the world by all the great artists of their time, always found in their sketchbooks but rarely seen in a finished work of art.
Modern art has however embraced charcoal as a popular medium for finished charcoal paintings and charcoal drawings.  Charcoal portraits are especially effective in capturing a subject’s character and subtle expressions.
Reproductions of the charcoal drawings and charcoal paintings of famous artists have become much admired, and valuable, artworks in their own right; the sketchbooks of Leonardo da Vinci for example.
Original and reproduction charcoal paintings and charcoal portraits are extremely durable once they have been mounted behind glass or sprayed with a fixative, or fine spray lacquer.