Answer:
The definition of quality of life is:
The standard of health, comfort, and happiness experienced by an individual or group.
This is a complex phenomenon because peoples standards are different based on many factors such as geographical location, and social standing.
Quality of life would be viewed much differently in third world countries that have a lot less privilege and more obstacles than first world countries have.
A person can however be happy without being rich. It is all about how someone views the world and how their brain sees comfort and happiness.