Short answers, pulled from the story.
Standard of living is the level of income, comforts and services available to an individual, community or society. It shapes a person's quality of life and depends largely on economic, social, political and environmental conditions outside personal control.
Standard of living is most often measured using inflation-adjusted income per person, though median income is considered more representative because income distribution skews the average. Other measures include poverty rates, healthcare quality, income inequality, educational standards and life expectancy.
Quality of life includes everything standard of living covers, plus intangible aspects such as leisure, safety, cultural resources, social life, physical health and environmental quality. Standard of living instead focuses on material and economic measures like income and access to services.
The biological standard of living refers to how well the human body fares within its socio-economic environment. It is most often measured using the height of a population.
An adequate standard of living was first described as a right in the Universal Declaration of Human Rights. The International Covenant on Economic, Social and Cultural Rights later expanded on that description.
The IPCC Sixth Assessment Report found that a decent living standard is achievable for everyone without fossil fuels, at roughly 15.3 gigajoules per capita by the end of the 21st century. This depends on improvements in sustainable development practices and more efficient technology and energy use.