15.7 THE MODERN INTERNET

The Internet has evolved from a small research network into a global communication system interconnecting billions of devices. It supports an extraordinary range of services, including web browsing, electronic commerce, cloud computing, video streaming, voice communication, industrial automation, and the rapidly expanding Internet of Things (IoT). Although these services appear very different to users, they all rely upon the same fundamental internetworking principles introduced in this chapter.

15.7.1 A Network Of Networks

Unlike a conventional communication network operated by a single organization, the Internet is a network of networks. It consists of many independently managed networks belonging to Internet Service Providers (ISPs), governments, universities, businesses, and private organizations.

Each organization manages its own internal network while exchanging traffic with neighboring networks through routers using common Internet protocols. This distributed architecture allows the Internet to continue expanding without requiring centralized control.