During flight, aircrafts generate static electricity by the friction of air. Generated static electricity stays on aircrafts body until being discharged and neutralized sufficiently.
Aircrafts use static dischargers to neutralize static electricity placed on the ailerons, elevators, rudder, winglets, horizontal and vertical stabilizer tips.
They are also known as static wicks. These devices neutralize electrical charges surrounding aircraft structure with their own high electrical resistance. These charges generated by either friction of air or clouds that carry negative electrons.
Electrical chargers generated by static electricity could produce radio frequency interference (RFI) which is a threat for safety of flight. Because RFI could interfere aircraft comminication and navigation equipment.
In addition static dischargers are not lightning arrestors so they do not protect aircrafts from lightning. Missing static wicks is a common event when lightning strike occurs on aircrafts. Due to extreme overload static wicks could blow up.