Inequality is not difference. Saying that people are unequal is saying that some are disadvantaged relative to others; inequality is disadvantage in a social context. The main inequalities in society are class, gender, race and inequalities in income and wealth.
Inequalities are usually represented in one of three patterns:
These issues are discussed further in the page on "welfare and society".
Social inequality is associated with social problems. The Spirit Level shows that societies which are more unequal tend to have not just more poverty, but more crime, more mental illness, more teenage pregnancy and so on. 
The inequalities which people are concerned with, Rae suggests, can concern
A policy which corrects one inequality (e.g. between women and men) can aggravate another (e.g. between rich and poor, if the beneficiaries are richer women). For example, there is a current argument in India that attempts to avoid gender discrimination will discriminate between castes.
Policies for equality can aim at
A measure is redistributive if the people who receive goods or services from a measure are not the same as the people who pay. All welfare provision is, by definition, redistributive in some way.
Redistribution does not have to be from rich to poor. Redistribution is conventionally classified as vertical or horizontal. Vertical redistribution may be progressive (from rich to poor) or regressive (from poor to rich). Horizontal redistribution goes from one kind of group to another - from men to women, households without children to families with children, tenants to owner-occupiers.
Egalitarian redistribution is progressive, but there are many ways to achieve equality, with different effects. Rae outlines four strategies:
Titmuss identified several different kinds of redistributive process, arguing that it was not possible to understand the redistributive impact of social policy without taking them fully into account. He referred to a 'social division of welfare', including three main types of welfare:
1. social welfare (the social services);
2. fiscal welfare (welfare distributed through the tax system); and
3. occupational welfare (welfare distributed by industry as part of employment). 
The classification is fairly crude. The category of fiscal welfare bundles together subsidies, incentives and transfer payments, including income maintenance. Occupational welfare includes perks, salary-related benefits, measures intended to improve the efficiency of the workforce and some philanthropic measures,. The classification excludes legal welfare (redistribution through the courts), the voluntary sector and the informal sector. The importance of the idea was, however,
Tawney argued that public spending is the most effective way of redistributing resources. The aim, he writes,
'is not the division of the nation's income into eleven million fragments, to be distributed, without further ado, like cake at a school treat, among its eleven million families. It is, on the contrary, the pooling of its surplus resources by means of taxation, and the use of the funds thus obtained to make accessible to all, irrespective of their income, occupation or social position, the conditions of civilisation which, in the absence of such measures, can only be enjoyed by the rich.' 
The provision of universal benefits helps to create equality in its widest sense - the reassurance provided by social protection.
Julian Legrand argues against this that the universal social services are not available equally to all. The universal National Health Service in the UK gives health care disproportionately to middle class people. The state provision of education tends to be regressive, partly because people are poorest when the children are young, but mainly because it is the middle classes who gain most from education after the age of 16. Transport subsidies are worth most to people who travel the greatest distances, who tend to be middle class. And housing subsidies tend to favour home owners, who are more likely to be wealthy. In his view, the 'strategy of equality' proposed by Tawney has failed. 
P Spicker, 2006, Liberty, equality, fraternity, Policy Press.