Freud's defense mechanisms include denial, displacement, projection, rationalization, reaction formation, regression, repression, and sublimation. Denial involves blocking out painful facts mentally, while displacement involves taking out feelings on someone else. Projection attributes one's own undesired thoughts to others, and rationalization justifies acts with good reasons. Reaction formation converts irrational thoughts positively, and regression reverts to earlier development stages due to fears. Repression buries bad thoughts that emerge symbolically, while sublimation redirects unacceptable drives constructively.