The Human Development Index (HDI) is a statistical composite index of life expectancy, education (mean years of schooling completed and expected years of schooling upon entering the education system), and per capita income indicators, which is used to rank countries into four tiers of human development. A country scores a higher level of HDI when the lifespan is higher, the education level is higher, and the gross national income GNI (PPP) per capita is higher.
Well-being, or wellbeing, also known as wellness, prudential value, prosperity 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.
Subjective well-being (SWB) is a self-reported measure of well-being, typically obtained by questionnaire. Ed Diener developed a tripartite model of subjective well-being in 1984, which describes how people experience the quality of their lives and includes both emotional reactions and cognitive judgments. It posits "three distinct but often related components of wellbeing: frequent positive affect, infrequent negative affect, and cognitive evaluations such as life satisfaction.
Quality of life (QOL) is defined by the World Health Organization as "an individual's perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards and concerns". Standard indicators of the quality of life include wealth, employment, the environment, physical and mental health, education, recreation and leisure time, social belonging, religious beliefs, safety, security and freedom.
The six-factor model of psychological well-being is a theory developed by Carol Ryff which determines six factors which contribute to an individual's psychological well-being, contentment, and happiness. Psychological well-being consists of self-acceptance, positive relationships with others, autonomy, environmental mastery, a feeling of purpose and meaning in life, and personal growth and development. Psychological well-being is attained by achieving a state of balance affected by both challenging and rewarding life events.