A lease, which is related to leasing (also known as renting), is a legal document, that can sometimes be a verbal agreement by which the rules are laid out for the renting process, giving a tenant the right to possess property belonging to the landlord. In other words it is the agreement that allows a tenant to move in to the home they don’t own as long as they pay the agreed amount of rent. The lease can be for a fixed period but it usually gives the landlord (owner of the property) the right to terminate the agreement at any time as long as they give a certain amount of prior notice to the tenant so they can look for other accommodation.
Leasing is not restricted to the typical house renting scenario. Other buildings such as offices or space needed to run a business can also be leased and in some cases large and expensive machinery can be leased out for the convenience of a business that cannot afford to buy the machinery outright. A common occurrence for businesses in financial trouble is to set up a sale and leaseback agreement with another company, where they sell the company some assets (usually machinery) to free up some capital and they then lease it back so they can still use it in operation, but no longer own it.
There is almost always some form of legal document involved with leasing and technically this document is the “lease”. This document is a contract between the two parties. In real estate the document is called the lease outright whereas things like DVD rental, the contract may be part of the signing up and membership process.