What's the difference between Indentured servitude and Bonded servitude?

An indentured servant is a person that has a contract to work without pay for the owner of the indenture for a set period of time. On completion of the contract, indentured servants were given their freedom, and occasionally plots of land or if the master was a craftsman tools of his trade. A bonded servant is a person who pledges their services as security for the repayment for a debt or other obligation, where the terms of the repayment are not clearly or reasonably stated, and the person who is holding the debt and thus has some control over the laborer. Freedom is assumed on debt repayment.] The services required to repay the debt may be undefined, and the services' duration may be undefined, thus allowing the person supposedly owed the debt to demand services indefinitely. Debt bondage can be passed on from generation to generation

Indentured servants were slaves who were free after serving a period of 7 years, provided they weren’t sold to another before the period was up, because if they were sold before the period was up, they would have to serve 7 years for that person...unless they were sold again. 

Bonded slaves had even less hope of ever being free.