PeopleSoft Internet Architecture is a server-centric, component-based architecture that allows secure internet access to PeopleSoft applications from any web-enabled device. It utilizes a database server to store data, application servers to run business logic and issue SQL queries, a web server to handle browser requests, and BEA Jolt to facilitate communication between the web and application tiers. This architecture provides benefits like easy access, platform independence, low bandwidth usage, and cost-effective maintenance compared to traditional client-server models.