HR outsourcing is a contractual agreement between an employer and an external third-party provider whereby the employer transfers the management of, and responsibility for, certain HR functions to the external provider. Many types of HR outsourcing options are available to employers. The options can be as specific as outsourcing one particular aspect of one HR function—such as applicant tracking for affirmative action purposes—or as broad as outsourcing the entire human resource department. The terms and types of arrangements prevalent in HR outsourcing are outlined below. See Small and Large Employers Outsource HR Duties Differently and HR Advice for a Department of None.