Budding is a method of asexual reproduction, whereas others follow sexual reproduction. Buds are unicellular structure develops an outgrowth (bud) on one side. The daughter nuclei produced through karyokinesis shift into the bud. The bud grows, constricts at the base, and separates.
So bud remains attached initially to the parent cells, which eventually separates and mature into the new organisms (cell). Unlike binary fission, the cytoplasmic division is unequal, and parental cell exists.
Eg., Hydra, Obelia, Yeast