Neurulation is the process during embryonic development where the neural tube forms, which eventually develops into the central nervous system, including the brain and spinal cord. This process begins shortly after the formation of the ectoderm, the outer layer of the embryo, which thickens to form the neural plate. As the neural plate folds inward, it creates a groove that deepens and eventually fuses to form the neural tube. Proper neurulation is crucial, as any disruptions can lead to neural tube defects, such as spina bifida or anencephaly, affecting the development of the nervous system.