Binary fission is a type of Asexual reproduction in which a single cell divides into two daughter cells (Binary means two and Fission means division into parts). The two daughter cells formed are exact genetic copies of the parent cell. This type of division is atypical of Amoeba, Paramecium, etc. (Note that in case of multiple fission, the parent cell divides into two or more than two cells).
Sexual reproduction, on the other hand, involves the fusion of two cells, a male cell and a female cell, to form new cell(s). Due to genetic recombination, the new daughter cell(s) have a combination of traits from both the parent cells. Sexual reproduction occurs in mammals like Humans, dogs, etc.