Business process outsourcing (BPO): It is a subset of outsourcing that involves the contracting of the operations and responsibilities of specific business functions (or processes) to a third-party service provider.

Information technology outsourcing (ITO): It is a company's outsourcing of computer or Internet-related work, such as programming, to other companies. It is used in reference to business process outsourcing, or BPO, which is the outsourcing of work that does not require many technical skills.

Knowledge process outsourcing (KPO): It describes the outsourcing of core business activities, which often are competitively important or form an integral part of a company's value chain. KPO therefore requires advanced analytical and technical skills as well as a high degree of proprietary domain expertise.

Legal process outsourcing (LPO): It refers to the practice of a law firm or corporation obtaining legal support services from an outside law firm or legal support services company.