1)Public sector: In the public sector, the government owns most of the assets and provides all the services. Railways or post office is an example of the public sector. The purpose of the public sector is not to just to earn profits. Governments raise money through taxes and other ways to meet expenses on the services render on it. Modern day government spend on a whole range of activities.
2)Private sectors: In the private sector, ownership of assets and delivery of services is in the hands of private individuals or companies. Companies like Techclyde Services Private limited or Reliance Industries Limited are privately owned. Activities in the private sector are guided by the motive to earn profits. To get such services we have to pay money to these individuals and companies.