The document discusses ego defense mechanisms, which are unconscious psychological strategies used to cope with reality and maintain self-image. Defense mechanisms can protect the mind from anxiety and help resolve mental conflicts. They are adaptive in small amounts but can become maladaptive and break down personality if overused. Adaptive defenses include repression, rationalization, intellectualization, compensation, sublimation, substitution, and displacement. Maladaptive defenses include denial, isolation, suppression, regression, reaction formation, and projection. The document provides definitions of specific defense mechanisms.