Differentiate internet,intranet and extranet

Internet	Is the worldwide, publicly accessible system of interconnected computer networks, which connects millions of computer all over the world.
Intranet	Is a private computer network that can be accessed only by authorized persons, especially members or employees of the organization that owns it
Extranet	is a private network that can be accessed only by authorized persons to securely share part of a business’s information or operations with suppliers, vendors, partners, customers or other businesses.