Well-being, also known as wellness, prudential value or quality of life, refers to what is intrinsically valuable relative to someone. So the well-being of a person is what is ultimately good for this person, what is in the self-interest of this person. Well-being can refer to both positive and negative well-being. In its positive sense, it is sometimes contrasted with ill-being as its opposite. The term "subjective well-being" denotes how people experience and evaluate their lives, usually measured in relation to self-reported well-being obtained through questionnaires. Sometimes different types of well-being are distinguished, like mental well-being, physical well-being, economic wellbeing or emotional well-being. The different forms of well-being are often closely interlinked. For examp