Define the terms privacy, confidentiality, and privilege

What will be an ideal response?

The right to privacy limits the access of other people to one's body or mind, including one's thoughts, beliefs, and fantasies. Privacy is a right of the individual, who alone can give it away. When a person reveals thoughts, behavior, and feelings to another person, privacy is lost.
In the context of therapy, the private information shared with a therapist is considered confidential. Confidentiality is an agreement between two parties (in this case, the therapist and patient) that private information revealed during therapy will not be discussed with others. The psychologist agrees to keep confidential the information that the patient reveals. Even if the patient decides to discuss that information, the psychologist still is bound by confidentiality.
The third concept is privilege, a legal term that prevents a therapist from revealing confidential information during legal proceedings. Sometimes physicians and psychologists hold privilege, meaning that they are legally protected against being forced to reveal confidential information in a legal proceeding. If communication is privileged, the psychologist cannot be compelled to reveal it in court (or any other legal setting). Privileged communication is not an automatic right of the therapist or the patient. Whereas confidentiality is considered to be an ethical commitment, privilege is established by state law. For mental health clinicians, privilege extends to therapists who are licensed to practice therapy in a particular state.