Frequently, you'll hear people say that "retirement age" is 65. What are they referring to?

Frequently, you’ll hear people say that "retirement age" is 65. What are they referring to? People who say this are referring to the age in which you can receive your full Social Security retirement benefits. At different ages starting at age 62, you are eligible to receive a percentage of the benefits, once you hit 65, you can receive your full percentage/allotted amount.