What network type is essentially a private internet for a company or organization?

The correct answer is intranet because an intranet is designed specifically for the exclusive use of a company or organization, functioning as a private network. It enables employees and authorized personnel to share information, resources, and applications in a secure environment, akin to how the internet operates but restricted to internal users. Intranets often utilize familiar internet technologies, which allows for effective communication and collaboration without exposing the internal network to external threats.

In contrast, an extranet is a controlled private network specifically for strategic partners, vendors, or suppliers to access a portion of an organization's intranet, effectively making it a bridge between the internal network and external parties. Bus topology and hybrid topology refer to different structural designs for network setups rather than describing the nature or purpose of the network itself.