An exchange-traded note (ETN) is a senior, unsecured, unsubordinated debt security issued by an underwriting bank. Similar to other debt securities, ETNs have a maturity date and are backed only by the credit of the issuer. ETNs are designed to provide investors access to the returns of various market benchmarks.
Do note that ETN can get terminated at any time. XIV is one such ETN that has been terminated suddenly.