Absolute poverty is a defined base, whereas relative poverty can change based on the society you are observing.
So although relative poverty in the US can define part of the population as in poverty, they can still be living above the absolute poverty line. Know the definitions, but understand the concepts too.
The cultural conflict between Sam and his parents is a common theme throughout the story. Neither side sees eye to eye with one another's views of the role of induviduals and money in society.