The equity of redemption refers to the right of a mortgagor in law

Law

Law is a system of rules and guidelines which are enforced through social institutions to govern behavior, wherever possible. It shapes politics, economics and society in numerous ways and serves as a social mediator of relations between people. Contract law regulates everything from buying a bus...

 to redeem his property once the liability secured by the mortgage has been discharged.
Historically, a mortgagor (the borrower) and a mortgagee (the lender) executed a conveyance of legal title to the property in favour of the mortgagee as security for the loan. If the loan was repaid, then the mortgagee would return the property; if the loan was not repaid, then the mortgagee would keep the property in satisfaction of the debt.