Indentured servitude is a form of labor in which a person is contracted to work without salary for a specific number of years. The contract, called an "indenture", may be entered voluntarily for a prepaid lump sum, as payment for some good or service (e.g. travel), purported eventual compensation, or debt repayment. An indenture may also be imposed involuntarily as a judicial punishment. The practice has been compared to the similar institution of slavery, although there are differences.
Historically, in an apprenticeship, an apprentice worked with no pay for a master tradesman to learn a trade. This was often for a fixed length of time, usually seven years or less. Apprenticeship was not the same as indentureship, although many apprentices were tricked into falling into debt and thus having to indenture themselves for years more to pay off such sums.