Sketching traditionally refers to a preliminary rough type of drawing that an artist might make in preparation for either a painting or a more formal drawing (like a study). A sketch is less detailed than a study - a study may be a highly detailed rendition of something to be used in a large composition. Of course sketching is also a form of doodling that a person may do to pass time with no end goal in mind. Formally however it is a useful way for an artist to capture a fleeting impression of a scene or person before it changes. For this purpose, it is typically executed rapidly and with little concern for accuracy. Not unlike caricature art, sketching is often about capturing a mood or key feature of the subject.