An economist's definition of poverty is a "condition where people's basic needs for food, clothing, and shelter are not being met." Anybody who has basic needs met, even if they have to skimp and save for them, is NOT poor.
In a modern economy, the definition of poverty is linked to money, because most transactions involve money (although not all - such as doing somebody a favour because they've done one for you), but bills and most consumer goods need money.
The "official" definition of poverty was (until recently) an income 60% below the MEDIAN income for people in a similar situation - please note, NOT the MEAN income. Therefore, in the UK people are classified as being in poverty if they have a household income below about £11,500. Four million people are below that threshold.
Relative poverty has been criticised because it actually reduces in a recession, although people are no better off, and it doesn't take into account different household needs. The Joseph Rowntree Foundation produces levels of absolute poverty, based on a "basket" of basic needs. Interestingly, the figure is very consistent with the level of relative poverty, usually slightly higher. Distinctions are made between housing and non-housing costs and households with different numbers of people.
The JRF's current poverty lines (after housing costs) are:
Single working-age adult £176pw
Pensioner couple £238pw
Couple with two children (age 2 and 8) £452pw
Lone parent with one child (age 1) £265pw
The vast majority of people who are totally reliant on benefits have an income below those levels. I find it even more shocking that two thirds of children whose parents receive benefits live in a household where at least one person works.
Whatever people's perception of poverty, four million people in the UK have a lower income than the above and do not have the choice to save, because their incomes are below what they need just to survive healthily in today's society.