An annuity is an insurance vehicle where a lumpsum amount is exchanged for a stream of payments going forward.  What makes a fixed annuity an annuity is that it has the option to annuitize at the end of the contract term.  You can also choose to leave your money invested at a renewable rate, withdrawal or a portion, or roll it over into a new fixed annuity.  Fixed annuities earn a fixed rate over multiyear time horizon.