Debenture is like a loan that someone takes from a company. Let's say that you want to buy a new toy but don't have enough money. You could borrow the money from the toy company with a debenture. The toy company will lend you the money and you have to pay them back later, with interest. Debentures are like loans, but instead of getting the money back from you, the company can get money from other customers by selling the debentures to them. So, you still owe the toy company the money you borrowed, but the company is also making money by selling the debentures to other people. It's like a loan layered on top of a loan.