This document provides an overview of debentures, which are a type of loan taken by companies from the public. It discusses the key characteristics of debentures, including that they are a written promise to repay the principal plus interest at a fixed rate by the company. The document also outlines the importance of debentures for companies and debenture holders. Finally, it describes the various types of debentures, such as secured vs unsecured debentures and redeemable vs irredeemable debentures.