"The Computer Network Expedition" is a beginner’s guide designed to bridge the essential need to understand networks and the internet in today’s connected world. While many people use technology daily, few truly grasp how devices communicate or how data moves. This book offers a structured, easy-to-follow journey—from what a network is to how it evolves into a computer network. Readers are guided step-by-step through how devices connect and how data flows using packets, wires, waves, protocols, and addressing. The book covers a wide range of essential topics: types of computer networks (by size like PAN/LAN/WAN, and by design like P2P), networking devices, packet-based data travel, transmission modes, and media (cables, fiber optics, waves). It explores wireless technologies like Wi-Fi (standards, security) and Bluetooth (BLE, profiles, speed, range), explains network models (OSI, TCP/IP), and delves into addressing (MAC, IP v4/v6, special types, ARP, DHCP, NAT). Routing is explained in detail (types, algorithms, tables, protocols like IGP, EGP, BGP). The book concludes by exploring the inter- net’s infrastructure, DNS, key protocols (HTTP, TCP, IP, UDP, ICMP), and security concepts like SSL/TLS, firewalls, and safe access.