The internet is a very different thing from an intranet, but many people get the two confused. The difference between "internet" and "intranet" comes down to one major thing: the internet is an open, public space while an intranet is designed as a private space. An intranet may be accessible from the internet, but it is protected by password and only open to authorized users.
The internet is a global system of interconnected networks, all of which use the Internet Protocol suite (TCP/IP). The internet is a huge world-wide "network of networks" which carries a vast array of information resources and services, such as the World Wide Web and eMail.
An intranet is similar to the internet, but it consists of a private network that uses Internet Protocol to share information within an organization. Intranets are common in workplaces where they allow employees to securely share information over a private network.
Intranet servers within a company often respond much more quickly than a typical internet website. This is because the public internet is at the mercy of traffic spikes, equipment malfunctions, and other problems, whereas the much smaller size of a private company intranet gives users more bandwidth and network hardware may be more reliable. This makes the transfer of high-bandwidth content easier over an intranet.
Besides the higher bandwidth and better reliability, company intranets can be beneficial because they allow employees in the field or those working at home to have easy access. With proper authorization, an employee can log in to a company intranet remotely and have access to the organization's information without compromising security. Employees can communicate with others in the company, submit their work, and do what they would normally do if they were in their office from anywhere with an internet connection.
An intranet is like a miniature internet within an organization's network; it can use any of the well-known internet protocols such as HTTP, SMTP, and FTP. Inter-linked web pages can be posted to an intranet like a mini World Wide Web. An intranet can greatly increase a company's productivity and cut down the cost of traditional communications.
The difference between the internet and an intranet is simple; one is public and the other private. An intranet can offer many benefits to an organization that would not come with a regular network and/or internet connection.