A debenture is a loan or debt using which a company or the government raises funds. This capital is then used to purchase assets, build roads and more, based on the entity issuing debentures. Usually, debentures are unsecured, but you may also come across secured debentures.
A common example of government-issued debentures is treasury bills and bonds. Issuing debentures helps a company to get access to finance without diluting its equity.