Retirement income sources are the various ways that individuals can receive income during retirement to support their living expenses. Common retirement income sources include:

1. Social Security: This is a government program that provides retirement, disability, and survivor benefits to eligible individuals based on their earnings history and age.
2. Retirement accounts: These include employer-sponsored retirement plans such as 401k s and individual retirement accounts (IRAs) that allow individuals to save and invest for retirement with tax advantages.
3. Pensions: These are retirement plans offered by some employers that provide a set amount of income to retirees based on their years of service and salary.
4. Annuities: These are financial products that offer a guaranteed stream of income for life or a set period of time in exchange for an upfront payment.
5. Personal savings: This includes savings in bank accounts, stocks, bonds, and other investments that individuals accumulate over time and can draw on during retirement.
6. Real estate: This includes rental income from investment properties, as well as the potential for appreciation in the value of real estate assets.

It is important for individuals to plan and diversify their retirement income sources to ensure that they have a secure and sustainable retirement.