how does binary fission differ from multiple fission

In binary fission, only 2 daughter cells are formed from the splitting of the parent cell. In multiple fission, many daughter cells are produced simultaneously from the parent cell. 

In binary fission, the parent nucleus divides only once, forming 2 nuclei. This is followed by cytoplasmic division, resulting in formation of 2 daughter cells.

In multiple fission,  the nucleus undergoes several divisions, producing a number of nuclei. After the nuclear divisions are complete, the cytoplasm separates, and each nucleus becomes encased in its own membrane to form an individual cell