Technical drawings are usually done using CAD software or a drawing board & parallel motion device. Fine art is done freehand, and genuinely taught more in schools because it can be interpreted and taught in many ways (paint, pastel, clay, photography, etc.). Technical drawings are used in engineering, architecture and the like; fine art is displayed in museums, given as commissions for personal use etc. as is it (usually) free of constraints and such. However, fine art can be used as 'concept drawings', so people can produce the technical drawings for it with all the measures on (again, engineering and architecture).
