Answer in detail.

Dear student,

Cleavage involves a series of mitotic divisions which results in enormous volume of egg cytoplasm to be divided into numerous smaller, nucleated cells

Whereas during gastrulation, cell movements cause reorganization of the embryo from a spherical blastula, into a multi-layered organism.

Thus the difference is that cleavage involves cell division while gastrulation involves just reorganization of the cells.

Regards