Internet is the grand, decentralized global network of interconnected computer networks that allows advanced, cheap, practically instantaneous intercommunication of people and computers and sharing of large amounts of data and information. Over just a few decades since its birth in 1970s it changed the society tremendously, shifted it to the information age and stands as possibly the greatest technological invention of our society. It is a platform for many services and applications such as the web, e-mail, internet of things, torrents, phone calls, video streaming, multiplayer games etc. Of course, once Internet became accessible to normal people and has become the largest public forum on the planet, it has also become the biggest dump of retards in history.
Internet is built on top of protocols (such as IP, HTTP or SMTP), standards, organizations (such as ICANN, IANA or W3C) and infrastructure (undersea cables, satellites, routers, ...) that all together work to create a great network based on packet switching, i.e. a method of transferring digital data by breaking them down into small packets which independently travel to their destination (contrast this to circuit switching). The key feature of the Internet is its decentralization, i.e. the attribute of having no central node or authority so that it cannot easily be destroyed or taken control over -- this is by design, the Internet evolved from ARPANET, a project of the US defense department. Nevertheless there are parties constantly trying to seize at least partial control of the Internet such as governments (e.g. China and its Great Firewall, EU with its "anti-pedophile" chat monitoring laws etc.) and corporations (by creating centralized services such as social networks). Some are warning of possible de-globalization of the Internet that some parties are trying to carry out, which would turn the Internet into so called splinternet.
Access to the Internet is offered by ISPs (internet service providers) but it's pretty easy to connect to the Internet even for free, e.g. via free wifis in public places, or in libraries. By 2020 more than half of world's population had access to the Internet -- most people in the first world have practically constant, unlimited access to it via their smartphones, and even in poor countries capitalism makes these devices along with Internet access cheap as people constantly carrying around devices that display ads and spy on them is what allows their easy exploitation.
The following are some stats about the Internet as of 2022: there are over 5 billion users world-wide (more than half of them from Asia and mostly young people) and over 50 billion individual devices connected, about 2 billion websites (over 60% in English) on the web, hundreds of billions of emails are sent every day, average connection speed is 24 Mbps, there are over 370 million registered domain names (most popular TLD is .com), Google performs about 7 billion web searches daily (over 90% of all search engines).
see also history
TODO (see https://www.zakon.org/robert/internet/timeline/)
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