What is the difference between cross-pollination from simple pollination?

In case of cross-pollination, pollen moves from one flower to another. So the pestle is pollinated by pollen, which was developed by stamens of another plant. Transfer takes place mainly due to insects that collect nectar. They transfer pollen on their own body. Simple pollination is essentially self-polling. Since pollen is produced by the same plant, on the flowers of which there is a stitch. In case of cross-pollination, the DNA of the plant occurs, so this method is better from an evolutionary point of view.