Social Security was originally introduced in 1935 in the aftermath of the Great Depression. It was intended to provide a safety net of income to retired and disabled workers and their families. Social Security is a mandatory plan, requiring most wage earners to contribute a percentage of their yearly income to support the program. In return, they, their spouses and sometimes their dependents are eligible for retirement, disability and survivorship benefits.
In order to plan realistically for the future you need to have a clear understanding of what money you need when you retire. This will include the cost of living and special activities you will have. It is estimated that you will need to replace 60% to 80% of your pre-retirement earnings in order to keep the standard of living you have had thus far.