The Passport segment called "Computers Are Bringing the World Closer Together" includes a module about the technology of Integrated Services Digital Networks, typically known as ISDNs. These communications networks are totally digital and will probably form the backbone of the emerging digital world. They can distribute many kinds of information at the same time via a broadband for video conferences, faxes, data communication, and voice lines for phone services. Simulations demonstrate the two most common methods for data transmission used in ISDNs: circuit switched networks and packet switched networks. Accompanying the module is a short self-quiz and access to the Passport glossary of technical terms.