The feathers on the back of arrows are also called fletchings. In this picture it shows three diferent style fletchings. The first has very little effect on straightening the arrow. The second makes the arrow spin faster. The third slows the arrow down and makes the arrow arc more. http://www.bowhunter-ed.com/images/graphics/ch4_types_fletching.gif#
While today's technology makes it far easier for an untrained archer to achieve a high rate of accuracy; there is nothing that compares with the satisfaction of mastering traditional archery. This is the ultimate benchmark for shooters reach. Anyone can shoot decently with telescopic sight, zero resistance rests, and a mechanical release. Becoming a competent traditional archer takes it beyond science and into the realm of art.