This document provides an overview of basic internet concepts including: 1. Networks connect computers and devices to allow communication between them using wires, wireless connections, or other virtual mediums. Protocols define rules for communication at both low and high levels. 2. TCP/IP is a core internet protocol suite with 4 layers - network interface, internet, transport, and application - that handle communication from hardware to applications. IP addresses and ports identify devices and applications. 3. Additional concepts discussed include domain name service, firewalls, protocol tunneling, and proxy servers which help network communication while providing security.