The document defines and provides examples of private, public, and voluntary sectors. The private sector consists of businesses not owned by the government, such as Tesco, Apple, and Primark. The public sector includes organizations run and funded by the government like schools, police stations, and the NHS. The voluntary sector comprises non-profit groups and charities that are neither run by the government nor intended to generate profit, including community groups, Oxfam, and Barnardo's.