OK, what are Contrails and Wingtip vortices?

The definition of 'Contrails/Vapor trails':

Contrails or vapor trails are condensation trails and artificial cirrus clouds made by the exhaust of aircraft engines or wingtip vortices which precipitate a stream of tiny ice crystals in moist, frigid upper air. Being composed of water, the visible white streams are not, in and of themselves, air pollution. However, contrails generated by engine exhaust are inevitably linked with typical fuel combustion pollutants. More Information here and here.

The definition of 'Wingtip vortices':

Wingtip vortices are tubes of circulating air which are left behind by the wing as it generates lift. One wingtip vortex trails from the tip of each wing. The cores of vortices spin at very high speed and they are regions of very low pressure. The cores of wingtip vortices are sometimes visible due to condensation of water vapour in the very low pressure. Wingtip vortices are associated with induced drag, an essentially unavoidable side-effect of the wing generating lift. Managing induced drag and wingtip vortices by selecting the best wing planform for the mission is critically important in aerospace engineering. Wingtip vortices form the major component of wake turbulence.