Binary fission and budding are both the procedures of asexual reproduction. They are both very identical; however, they do possess certain differences. They are regarded as the most basic methods of asexual reproduction.
Binary fission takes place majorly in unicellular species. When the species has to reproduce its cell goes via the phases of mitosis. However, when it attains cytokinesis it divides into two distinct organisms.
Budding is another kind of asexual reproduction. In this process, a new species called bud originates from the original organism. As soon as the bud possess the tendency to survive on its own it distinguishes itself from the original organism.
It takes place in both the multicellular organisms and unicellular organisms. However, unlike binary fission, it takes place from an unequal division of the reproducing organism.