When the lease is over, the dealership will sell that vehicle for its residual value. The residual value is the price the dealership believes the vehicle will bring on the used car market two or three years down the road. So you are paying the difference between the resale price and the agreed-upon price. Sounds good, but there are a lot of potholes along the way. The most important thing to first consider is how much you intend to use the vehicle.
Mileage is the key.
Go above that number of miles and you pay somewhere in the neighborhood of 15 cents for every mile over the agreed-upon number in the lease. If you think you might want to buy the vehicle at the end of the lease, get an agreed-upon price in writing at the outset. You don't just walk away at the end of the lease. If your mileage is over the limit, you pay. That has happened and could happen again, especially if you buy a vehicle with no track record.