With a lease-option, you rent a house and have the right (but not the obligation) to buy it.
With a lease-purchase, you rent a house and you also agree to buy it at some point in the future.
With a lease-option, there's usually an up-front option fee credited to the purchase price if you decide to buy. It's NOT a down payment. You don't get it back if you change your mind about buying.
With a lease-purchase, there may be an up-front down payment.
Typically, with either, a portion of your rent (it could be 10%-30%, more or less) is credited to the purchase price of the house.
Both have time-limits in which you can/must buy. That may be anywhere from 6 months (with a lease-purchase) or a year or so (with a lease-option) to 3-5 years.
Is it a good idea? Sometimes. It's not if you're able to buy today. It's not if you won't be able to even in a few years. But it often is if you're not able to buy now, but you think you'll be able to in 2-4 years.
Make sure you have a lawyer who understands rent-to-owns review all the documents before you sign.
Here's a link to a blog I wrote on how to find rent-to-own properties: http://bit.ly/findaleaseoption
Hope that helps.
There a couple of ways you can work the opt to buy out. is it is a good idea? I would say that depends on your individual situation and the agreed upon terms. if you want to discuss it further feel free to contact me.