Feathers are bound to the arrow’s shaft and act as airfoils to provide a small amount of force used to stabilize the flight of the arrow.
They are necessary to stabilize the arrow in flight and prevent it from tail yaw. That’s why missiles have fins on them. Fletching (Traditionally called Feathers) is designed to keep them in the right direction during a flight.
If you shoot an arrow without fletchings, It will not spin when it passes from the bow riser. Without Fletchings, an arrow is just like a stick.
If you throw the stick from your hand, It will go a little farther and fall off. But if you fletch that stick, the fins will stabilize its flight and it will go far away with accuracy.
” THE RESON FOR FLETCHING IS TO SPING THE ARROW WITH AERODYNAMICALLY. “
Feathers were traditionally attached to the arrows with glue and silk thread but we have not seen such arrows these days. But now, Fletchings are made of modern plastic, rubber or wood.