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How does the fetal period differ from the embryonic period?

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A series of medical illustrations showing the stages of childbirth: the baby's position at the onset of labor, flexion, internal rotation of the head, extension, external rotation of the head, and the uterus immediately after birth with the placenta and umbilical cord. — birth Sequential changes in the position of the child during labour.

In human prenatal development, the embryonic and fetal periods are distinct stages defined by their primary biological processes and timing.1

Embryonic Period: This stage occurs from the third to the eighth week of development. It is primarily characterized by organogenesis, the critical process during which the major organs and external body structures are formed. By the end of the second month, the developing organism has acquired a recognizably human form.12
Fetal Period: Beginning after the eighth week and continuing until birth, this stage is defined by the maturation of tissues and organs that were established during the embryonic phase. The fetal period is also marked by rapid body growth.1

While the embryo is focused on the foundational development of its systems—such as the heart, limbs, and nervous system—the fetus focuses on the refinement and functional growth of those structures to prepare for life outside the uterus.134