Forms of public sector:
Out of the several forms of public sectors few are:
(A) Government department:

• A public sector unit run and managed either by state or central government as per the laws, rules and regulations of either state or central government or both is called a government department. The employees working in these units are called government employees.
• For example, Postal department, Railway etc. are government departments.

(B) Public corporation :

• Public corporation is a corporation which comes into existence through a special act of Parliament or Legislative Assembly i.e. Vidhan Sabha. The authority to run these units, the powers, duties, rights and responsibility and labour laws are all as per the special act passed in the Parliament.
• For example, Indian Airlines, Food Corporation of India, Gujarat State Textbook Board etc. are all public corporations.

(C) Government Companies

• A company established as per the Companies Act and in which minimum 51% state is with State or Central Government or both together is called a government company. Since the government owns the largest stake of shares in such companies they are called government companies.
• For example, Hindustan Machine Tools (HMT), Hindustan Aeronautics Ltd., etc.