What is a difference between self-pollination an cross- pollination?

The difference between self a pollination and cross a pollination is:

Self- pollination occurs when the pollen from the anther is deposited on the stigma of the same flower, or another flower on the same plant.

Cross-pollination is the transfer of pollen from the anther of one flower to the stigma of another flower on a different individual of the same species. Like bees and butterflies.

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