Until fairly recently, most major car manufacturers does not really encourage the leasing of vehicles to private customers, it was a part of the business that was more reserved for companies and fleets.
That has changed significantly, and nowadays all major car companies actively promote the idea of leasing a vehicle, making it a viable option for private individuals as opposed to buying a car outright.
Leasing a car should really be thought of as a long term rental. Many people like the idea of being to lease their car, simply because it enables them to have one in a way that they would not otherwise be able to afford.
The obvious downside of leasing a car is at you do not have ownership of it, you do not own the title of vehicle. At a practical level, this means that you cannot really make many modifications or changes to the vehicle, and you have to give it back at the end of the lease period.
The decision as to whether to buy or lease a vehicle specially stems from the above distinction. For many, the idea of leasing has a number of benefits that outweigh the issue of ownership of the vehicle or ownership of title.
A car lease is a fixed long term contract, normally anything up to 72 months. There is a fixed monthly repayment cost, which is largely based upon the depreciation of the value of the vehicle over the term of the lease.
There will be other conditions such as a fixed mileage allowance over the term of the lease, and possibly on an annual basis as well
There is normally an option to purchase additional mileage, and the costs of this should be spelt out in the terms and contracts of the lease agreement.
Aside from having access to a vehicle that the individual might not otherwise be able to own that are also normally significant financial benefits to be had by leasing a car. Many manufacturers offer very specific finance deals on car leases, often with 0% interest, assuming your credit rating is good enough to qualify for it.
With any lease agreement, all the costs should be spelt out and clarified at the beginning of the lease period. This includes what is normally referred to as the lease end agreement. This is costs associated with wear and tear of the vehicle.
The intent of the manufacturer is to put the vehicle into a condition that would be appropriate given its age and mileage. If the car has excessive wear and tear over and above what is deemed to be appropriate, then there will be charges levied against the lessee in order to cover the difference.