1. Number of members: A private company can be registered with two members while a public company must have at least seven members. A private company cannot have more than fifty members excluding its past and present employees. A public company can have any number of members. 

2. Invitation to the public: A private company cannot invite the public by issue of the prospectus to subscribe to its share capital. On the other hand, a public company is free to invite public to subscribe to its share capital. However, it is under no legal binding to invite public to subscribe to its shares or debentures. 

3. Transferability of shares: There is a restriction on the transfer of shares in a private limited company. The transfer shall not be allowed unless agreed to by all the existing members of the company. 

4 Commencement of business: A private company can start its business immediately after incorporation. A public company must obtain the certificate of commencement of business before starting its business operations. 

5. Articles of association: A private limited company must prepare and file its own articles of association. But a public limited company may adopt the model Articles as given in the Companies Act.