Self pollination is the opposite of cross pollination.
Here, transfer of pollen from the style to the stigma occurs within the same flower, or sometimes between flowers, but always on the same plant. There is no “crossing over” of pollen from one plant to another.
Self pollination, although rarer than cross pollination, occurs in a wide range of plant families such as Orchidacea, Fabaceae, Asteracea, and Poaceae.