Social insurance is a form of social welfare that provides insurance against economic risks. The insurance may be provided publicly or through the subsidizing of private insurance. In contrast to other forms of social assistance, individuals' claims are partly dependent on their contributions, which can be considered insurance premiums to create a common fund out of which the individuals are then paid benefits in the future.

Welfare, or commonly social welfare, is a type of government support intended to ensure that members of a society can meet basic human needs such as food and shelter. Social security may either be synonymous with welfare, or refer specifically to social insurance programs which provide support only to those who have previously contributed, as opposed to social assistance programs which provide support on the basis of need alone. The International Labour Organization defines social security as covering support for those in old age, support for the maintenance of children, medical treatment, parental and sick leave, unemployment and disability benefits, and support for sufferers of occupational injury.