A fœtus is the developing stage of a human or animal after the embryonic phase and before birth. In humans, this stage typically begins around the 8th week of pregnancy and lasts until delivery. During this time, the fœtus undergoes significant growth and development, forming essential organs and systems. The fœtus is nourished through the placenta, which connects it to the mother. This organ provides oxygen and nutrients while removing waste products. The fœtus can also respond to external stimuli, such as sounds and light, as it prepares for life outside the womb.