Social security is a government program that provides a fixed monthly payment of money to people over 68 years old. The great U.S. President Franklin Delano Roosevelt created it in the 1930's. Workers pay for it by having a small amount taking out of their paycheck every month, which the government invests very safely. Then, when they retire, they receive a check in the mail every month from the government. Social security is a very important issue in the U.S. presidential campaigns because older people tend to vote more than younger people.