Sapna Nayak discusses how Postman provides both public and private API networks. The public API network allows developers to discover and connect with APIs from various developers and organizations. It acts as a map or directory. The private API network allows teams to share important internal APIs, provide discovery within the organization, and details on how to use APIs. Both networks allow connecting APIs in Postman workspaces. Search is also introduced to help find APIs across Postman collections.