Sigmund Freud is the founder of psychoanalysis and is known for his work on the unconscious, which he believed is a reservoir of repressed thoughts, feelings, and desires.

Displacement is a defense mechanism in which an individual unconsciously displaces their feelings from one object to another, often a less threatening one.

The Oedipus complex is a psychoanalytic theory that describes a boy's unconscious desire to kill his father and marry his mother.

Sublimation is a defense mechanism in which an individual unconsciously transforms unacceptable impulses into socially acceptable ones.

The Electra complex is a psychoanalytic theory that describes a girl's unconscious desire to kill her father and marry her mother.

Jacques Lacan is a French psychoanalyst who is known for his work on the concept of the mirror stage, which is a developmental stage in which a child first recognizes itself as a separate individual.

Projection is a defense mechanism in which an individual unconsciously attributes their own thoughts, feelings, or desires to another person.

The id is the part of the personality that is concerned with pleasure and gratification.

Melanie Klein is a British psychoanalyst who is known for her work on the concept of object relations, which is the study of the relationships between individuals and the objects in their environment.

Rationalization is a defense mechanism in which an individual unconsciously creates a false or distorted explanation for their behavior.

The ego is the part of the personality that is concerned with reality and logic.

Carl Jung is a Swiss psychoanalyst who is known for his work on the concept of the collective unconscious, which is a reservoir of shared memories, symbols, and archetypes that is common to all humans.

Repression is a defense mechanism in which an individual unconsciously forgets or represses painful or traumatic memories.

The superego is the part of the personality that is concerned with morality and ethics.

Sigmund Freud is the founder of psychoanalysis and is known for his work on the concept of the death drive, which is a fundamental human drive towards self-destruction.