How do different cell types (tissues) arise from a single cell

How do different cell types (tissues) arise from a single cell?

First, the zygote (sperm + egg) (which is the "single cell") undergoes cleavage to form a blastula. That blastula will then undergo gastrulation to form three germ layers which will develop into various TISSUES of the body. The germ layers; ectoderm will develop into skin and nervous system, mesoderm will develop into muscle, most internal organs, and connective tissue including bone and cartilage, and the endoderm develops the linning of the digestive tract and gut.

-----> if you were curious, after gastrulation, organogensis takes place, which is the actual process of tissue and organ formation.