The mechanism which brings pollen grains on to the surface of stigma is pollination.
True
Pollination is the process by which pollen is transferred to the female reproductive organs of a plant, thereby enabling fertilization to take place. It is usually carried to the female plant by a pollinator, that is a biotic agent or vector that moves pollen from the male anther of a flower to the female stigma of a flower to accomplish fertilization or 'syngamy' of the female gametes in the ovule of the flower by the male gametes from the pollen grain.