This document discusses the history and components of the Internet and how it has evolved. It describes how the Internet started as a network called ARPANET developed by the US Department of Defense in the 1960s and 1970s using the TCP/IP protocol. It later became commercially available and grew to include many networks worldwide. The document also provides examples of some common applications and services used over the Internet today like email, websites, search engines, online shopping, social media, and file sharing.