Leasing is when you want to buy something very expensive, like a factory, machinery, etc., but you don't have enough money for it. And this is where the leasing provider comes in: they buy this machinery from the seller (the leasing vendor) for you (your dear self) and give it to you for use. Not for free, but with interest, usually for decades or more (under a contract). And every month you use this machinery, paying a small amount for its use. When the time expires, the price of that very machinery should drop by about 80% from its initial price. And this machinery becomes yours by right.

​This is just to understand the term itself—leasing. In reality, if you dig deeper, it is a big part of jurisprudence.