In business, commerce, and economics, a client is a person who receives advice or services from a professional, such as a lawyer or a health care provider. Clients differ from customers in that customers are thought of as "one-time buyers" while clients can be summarized as "long-term recipients." 
Therapeutic relationships are subject to confidentiality, meaning that therapists are not to disclose information shared by their clients during sessions, to those not involved in the session. However, there are a number of exceptions in which a therapist can and must "break" the confidentiality, such as when the information suggests that the client poses an immediate threat to himself or herself or to others.  
Lawyers and attorneys also have clients. An important aspect of a lawyer's job is developing and managing relationships with clients or, if the lawyer works for a government agency or corporation, the client's employees. Lawyers give legal advice to their clients as part of the legal process. 
- "What Is the Difference Between a Customer Vs. a Client?". Chron. Retrieved March 7, 2019.
- "Client origin and meaning of client". Online Etymology Dictionary.
- "Patients or Clients?". August 4, 2013.
- Stone, Alan (December 1976). "The Tarasoff Decisions: Suing Psychotherapists to Safeguard Society". Harvard Law Review. 90 (2): 358.
- Welfel, Elizabeth Reynolds (2016). Ethics in counseling and psychotherapy : standards, research, and emerging issues (6th ed.). San Francisco, CA: Cengage Learning. p. 129. ISBN 9781305089723.
- Ellman, Stephen (1987). "Lawyers and Clients". UCLA Law Review. 34: 717.