Other forms: private sectors
In economics, everything that's not part of the government is known as the private sector. Unlike working for the United States Postal Service, delivering packages for UPS or Fed Ex is a job in the private sector.
In economics, there's the public sector (jobs connected to the government) and the private sector, made up of privately owned companies. Public school teachers aren't in the private sector, but your neighborhood coffee shop and the local dog walker do belong to that part of the economy. Sector, from a Latin root meaning "to cut," was originally used in geometry to mean "part of a circle," and its meaning expanded to "area, part, or branch of the economy."