.The transfer of pollen grains from the anther to the stigma of a flower.

.pollen grains are im mobile they cannot reach the stigma by them selves an external agent is required for this.it can be wind water animal,gravity or grow contact

two types of pollination

.self pollination

.cross pollination

self pollination

.cross pollination it is the transfer of pollen grains from the stigma either the same genetically similar flower.

.Accordingly self pollination is of two types autogamy

and geitonogamy