Puppy stages refer to the developmental phases that puppies go through from birth to adulthood. The main stages include the neonatal stage (0-2 weeks), where puppies are blind and rely on their mother for warmth and nutrition, and the transitional stage (2-4 weeks), when they begin to open their eyes and ears. The socialization stage (4-12 weeks) is crucial, as puppies learn to interact with their environment and other animals. Finally, the juvenile stage (3-6 months) involves increased independence and energy, as puppies continue to grow and develop their personalities. Proper training and socialization during these stages are essential for a well-adjusted adult dog.