The public sector is a part of the state that deals with the delivery of goods and services by and for the government, whether national, regional or municipal. The organization of the public sector. Direct administration funded through taxation the delivering organization generally has no specific requirement to meet and production decisions are determined by government.
Publicly owned corporations which differ from direct administration in that they have greater commercial freedoms and are expected to operate according to commercial criteria and production decisions are not generally taken by government although goals may be set for them by government. Partial outsourcing of the scale many businesses is considered a public sector model.
A borderline form is Complete outsourcing or contracting out, with a privately owned corporation delivering the entire service on behalf of government. This may be considered a mixture of private sector operations with public ownership of assets, although in some forms the private sector's control and/or risk is so great that the service may no longer be considered part of the public sector.
In spite of their name, public companies are not part of the public sector a particular kind of private sector that can offer their shares for sale to the general public. The decision about what are proper matters for the public sector as opposed to the private sector is probably the most important socialist liberals favoring state involvement in some aspects of the economy but not others.