A landlord agrees to give a renter an exclusive option to purchase the property. The option price is usually determined at the outset, but not always, and the agreement states when the purchase should take place—whether, say, six months, or a year or two down the road.
A portion of the rent is used to make the future down payment. Most lenders will accept the down payment if the rental payments exceed the market rent and a valid lease-purchase agreement is in effect.
Before you opt to do a lease option, find out as much as possible about how they work. Talk to real estate agents, read published materials, and, in the end, have an attorney review any paperwork before you sign on the dotted line.