By paying premiums into the mutual pension division of a pension fund, the member accumulates certain rights. When the time comes, the fund member will receive a pension. The premium, moreover, ensures the payment of disability, spouse or child pensions if necessary.
One could say that by paying into a mutual pension division, the fund members are mutually guaranteeing each other pensions to the end of life. The same applies if a fund member suffers loss of income due to permanent loss of ability to work. If the fund member passes away, the surviving spouse or children, moreover, are entitled to pension payments for a certain time.