He didn't want to break away from psychoanalysis but rather to extend it. He extended the stages of development to go throughout life. He gave emphasis to the ego over the id. Erikson believed that the ego is the part of the mind that gives coherence to experiences, conscious or unconscious. Different societies with different child rearing practices tend to shape personalities that fit the needs and values of their culture.
Term comes from embryology.
At each successive stage, the human personality becomes more complex. The stage are interactions between biological development, psychological abilities, cognitive capacities, and social influences. Each stage is present in potential from birth on but doesn't take center stage until its proper time. It also continues to exist throughout all later stages. Each stage centers around an emotional polarity or conflict that people encounter at certain critical periods.