What term refers to a secure internet-based network connecting buyers and suppliers?

The term that refers to a secure internet-based network connecting buyers and suppliers is an extranet. An extranet is designed to facilitate communication and information sharing between businesses and their external parties, such as suppliers and customers. It provides a controlled access layer to a company's internal systems and resources while ensuring that sensitive information is protected. This collaboration allows for more efficient processes such as order processing, inventory management, and customer relationship management.

In contrast, an intranet is a private network accessible only to an organization's staff, focusing on internal communication rather than external connections. An internet marketplace is a broader term for platforms where various sellers can present their products to the public, but it does not specifically denote a secure network for direct connections between buyers and suppliers. An e-commerce platform refers to a system that facilitates online sales transactions but does not inherently imply the security and exclusivity that characterize an extranet environment.