In plants during sexual reproduction pollen grain from the anther of a flower reach to stigma. This transfer of pollen occurs naturally by air, birds, insects etc. Once pollen reaches the stigma it moves toward the ovum by chemotaxis. We call this process pollination.
Fertilization is the fusion of two gametes. It is a broader term which we apply to all organism reproducing sexually.
Pollen reaches inside the stigma and fuses with the ovum. This is also a type of fertilisation. If a male game of an animal fuses with the female gamete it is also a type of fertilisation.
Next: What could be the reasons for adopting contraceptive methods?
See also: How is the process of pollination different from fertilisation?
