In general the concept of an annuity is stupid. One can go receive a higher cash flow from an annuity than a bond or a stock that pays out a monthly dividend. There are several types of annuities but in short, one gives a large lump sum typically to an insurance company and they pay monthly, quarterly or yearly, depending on the annuity.
Rest of this article is on my website here:
https://www.tskjesusfreak.com/blog/annuities-suck