We have numerous pages here that cover various aspects of Structured Settlement. While I strongly suggest you read a few of them to get a more complete picture of this rather interesting topic, here is a brief (and therefore mostly inadequate) answer to your question:

Structured settlement is essentially an agreement that specifies how a recipient of a settlement will get paid over time -in predetermined installments. These kinds of "structured" periodic payment arrangement are made when both the parties (the payer, and the recipient) agree to exchange the monetary settlement award in a set of periodic payment over time instead of getting a (often a relatively smaller) onetime lumpsum payment.

Structured settlements are often used to pay for large Lottery winnings, personally injury awards, compensatory and/or punitive damages, compensation for the victims (or their families) of occupational injuries. It is also often a good way to set aside money for ensuring continued/longterm care for a minor or someone that needs longterm/lifelong care and support.

Such settlements can sometimes be sold at a discounted rate, and there are a whole range of legal/taxation related issues that apply to it. I suggest you read various other documents we have published here at this site for more complete answers/details than what I have briefly stated above.