Self-pollination and cross-pollination are the two types of pollination. Self pollination occurs in certain plants when pollen falls directly onto the stigma of a single flower, resulting in successful pollination.
Cross-pollination is more complex and requires pollen from the anther plant, pollen of one flower is transferred to the stamen of another flower. Cross pollination occurs via wind, water, or animals. Wind pollination occurs when pollen grains are loosened from the anthers of a flower, carried by the wind, and land on another flower. Water pollination is similar, but instead of wind, water transferred the pollen. Pollination by animals is required by the vast majority of plants, and is carried out by honey bees, bumblebees, and butterflies, among other insects and animals.