The Internet uses the communication sector to link computers, cellular telephones, and tablets; transportation systems; water and power systems; and industrial control systems together. It extends the communication sector to applications such as the World Wide Web (WWW), email, video streaming, and face-to-face conferencing. A more precise technical definition defines the Internet as a global network that uses Transmission Control Protocol/Internet Protocol (TCP/IP). While the Internet has been around for nearly 50 years, it began to spread like an epidemic only after TCP/IP was created and adopted by the U.S. Department of Advanced Research Projects Agency (ARPA and later Defense Advanced Research Projects Agency (DARPA)). TCP/IP is the lingua franca of global communications and the basic “building block of the Internet’s DNA.”

The Internet started as an idea on paper and grew into one of the largest man-made machines in the world. Experts fully expect that all 7 billion inhabitants of the globe will eventually be on the Internet—perhaps by the mid-2020s. But the spread of TCP/IP goes beyond the population of the planet. Billions more machines communicate via the Internet from automobiles, factories, power grids, gas and oil pipelines, water systems, and everyday products. The Internet will eventually connect more machines together than people—perhaps as many as 100 billion machines and 7 billion people will be linked via TCP/IP in the near future.

The global spread ...

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