Consent is a subject many people think they understand. In reality, it is much more complex than it appears and is often poorly understood. The confusion around consent can give rise to serious legal and ethical issues, especially given that it is a foundational concept in both privacy and UI/UX design. This course covers the elements of consent and its many different forms, including active, passive, explicit, implicit, implied, opt-in, and opt-out; clarifies the distinction between consent and similar concepts; explains where consent is required; and points out what invalidates consent.