What term describes a private network that operates similarly to the Internet but is only accessible to specific users?

The term that describes a private network operating similarly to the Internet but accessible only to specific users is "Intranet." An intranet is typically used by organizations to facilitate secure communication and sharing of information internally among employees or members. It relies on web technologies but is confined to the organization's private network, providing a controlled environment for access, which enhances both security and privacy.

While the other terms describe various network types, they do not meet the criteria outlined in the question. For instance, an extranet provides controlled access to external users, such as partners or clients, extending beyond the immediate organization but still not open to the general public like the Internet. The World Wide Web and the Internet refer to the global network of accessible information and connections available to anyone, lacking the restriction of being private or exclusive to particular users.