Private limited company
A private limited company can have a minimum of two members and a maximum of two hundred members. The directors of a private limited company have limited liability to their creditors and Banks/Creditors are allowed to sell only the assets of the company (when there is a scenario of default).
Section 8 Company
A company is referred to as Section 8 Company when it registered as a Non-Profit Organization (NPO) i.e. when it has motive of promoting arts, commerce, education, charity, protection of environment, sports, science, research, social welfare, religion and intends to use its profits (if any) or other income for promoting these objectives.
"A nidhi company is a type of company in the Indian non-banking finance (NBFC) sector, recognized under section 406 of the Companies Act, 2013. Their core business is borrowing and lending money between their members. It inculcates the habit of saving among its members and works on the principle of mutual benefit."
One Person Company (OPC)
As per Section 2(62) of the Company’s Act 2013, a company can be formed with just 1 Director and 1 member. It is a form of a company where the compliance requirements are lesser than that of a private company.