Asexual reproduction method in which a portion of the cell body is thrust out and then becomes separated, forming a new individual.
Common in plants, fungi, and some animal organisms, such as hydra and yeast. Usually the protrusion stays attached to the primary organism for a while, before becoming free.
The new organism is genetically identical to the primary one (a clone). When yeast buds, one cell becomes two cells. When a sponge buds, a part of the parent sponge falls off and starts to grow into a new sponge.