(i) The transfer of pollen grains from anther of a stamen to the stigma of a carpel is called pollination whereas fertilisation is the process when the male gamete present in pollen grain joins the female gamete present in ovule.
(ii) Pollination is an external mechanism whereas fertilisation is an internal mechanism which takes place inside the flower.
Site of fertilisation in flower is ovary.
Product of fertilisation in flower is zygote.