Hypothec, sometimes tacit hypothec, is a term used in civil law systems or to refer to a registered real security of a creditor over real estate, but under some jurisdictions it may additionally cover ships only, as opposed to other collaterals, including corporeal movables other than ships, securities or intangible assets such intellectual property rights, covered by a different type of right (pledge). Common law has two main equivalents to the term: mortgages and non-possessory lien.

In lending agreements, collateral is a borrower's pledge of specific property to a lender, to secure repayment of a loan. The collateral serves as a lender's protection against a borrower's default and so can be used to offset the loan if the borrower fails to pay the principal and interest satisfactorily under the terms of the lending agreement.