WINGLETS

Winglets or sharklets, the name might be different but the purpose is the same.

1.   The top and bottom wing surface have a large pressure differential between them this cause the lower air to run upwards at the edges of wings.

2.  To prevent them from moving up and causing induced drag and resulting in much fuel consumption a barrier has to be set between them.

3.      This barrier is the winglet that separates them effectively thereby reducing the possibility of those airstreams casuing ineffectiveness to outboard flight control surfaces over the top surface.

Winglets,and their purpose is to reduce turbulence at the tips of an airplane’s wings. The air pressure on the bottom of a wing is greater than the pressure on top, so when air flowing across the two surfaces meets at the wing tip, it forms a vortex-a miniature tornado.

By. @flight_no1

Image sources : https://www.quora.com/Why-are-winglets-pointed-upwards