What are defense mechanisms and what are the major types?

Defense mechanisms are unconscious strategies the ego uses to reduce anxiety caused by conflicts between the id, superego, and reality. Major types include repression, which pushes threatening memories into the unconscious; denial, which refuses to accept reality; projection, which attributes one's own unacceptable feelings to others; rationalization, which creates logical explanations for irrational behavior; displacement, which redirects emotions to a safer target; sublimation, which channels unacceptable impulses into socially acceptable activities; regression, which returns to behavio