An annuity is a broad class of financial agreements struck between an individual or company. These are often agreed to be the most ideal way to receive payments (reciprocation) over the course of a person's lifetime. The majority of annuities are purchased, as in a 401 K plan. Structured settlements differ from this definition, in that these settlements are issued as a result of a court award, such as in a personal injury case.
The benefits of an annuity may be started immediately, or can be postponed until retirement, etc. The important thing to consider, is why these long-term payments are made in your own best interest, there are other events that may influence you to decide to sell these payments early, in order to collect either a portion, or a lump-sum of your remaining payments. The most common reasons include debt, investment, medical emergency, schooling, or large purchase.
The most important thing to consider before selling any annuity, is how to maximize your payout.