The following stages should be described in detail:
Oral stage (birth to 12 to 18 months): The mouth is an infant's main source of pleasure and exploration. Weaning is the key developmental task to be accomplished during this phase.
Anal stage (12 to 18 months to 3 years): The anus is the toddler's source of pleasure: children gain pleasure from both the retention and expulsion of feces. Toilet training is the main task to be accomplished in this stage.
Phallic stage (age 3 to age 5 or 6): The focus in this stage is on the genitals and the pleasure derived from fondling them. The key task in this phase is handling the Oedipal conflict.
As children focus on their genitals, the difference between male and female anatomy becomes apparent. A young boy becomes attracted to his mother. He sees his father as a rival and wishes to kill him. The boy fears that the father, who is larger and more powerful, may castrate him. Thus, the boy represses his desire for his mother and begins to identify with his father so that he may possess a woman like his mother.
A young girl blames her mother for her "missing" penis. Ultimately, however, she begins to identify with her mother so that she can one day incorporate the penis of a man like her father.