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1. www.britannica.com › technology › VPNVPN | Definition & Facts | Britannica

   www.britannica.com › technology › VPN

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   2024年4月27日 · VPN, a private computer network deployed over a public telecommunications network, such as the Internet. A VPN typically includes one or more connected corporate intranets, or local area networks (LANs), which users at remote locations can access using a password authentication system.

   • 作者: The Editors of Encyclopaedia Britannica

2. www.britannica.comEncyclopedia Britannica | Britannica

   www.britannica.com

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   Discover all you need to know about retirement, investing, and household finance, without the jargon or agenda. Get reliable guidance, insight, and easy-to-understand explanations, written, edited, and verified to Britannica’s exacting standards. Presenting Advocacy for Animals, a blog focused primarily on animal rights, wildlife conservation ...

3. www.britannica.com › technology › InternetInternet | Description, History, Uses, & Facts | Britannica

   www.britannica.com › technology › Internet

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   • Overview
   • Early networks

   The Internet is a vast network that connects computers all over the world. Through the Internet, people can share information and communicate from anywhere with an Internet connection.

   Who invented the Internet?

   The Internet consists of technologies developed by different individuals and organizations. Important figures include Robert W. Taylor, who led the development of the ARPANET (an early prototype of the Internet), and Vinton Cerf and Robert Kahn, who developed the Transmission Control Protocol/Internet Protocol (TCP/IP) technologies.

   How does the Internet work?

   The Internet works through a series of networks that connect devices around the world through telephone lines. Users are provided access to the Internet by Internet service providers. The widespread use of mobile broadband and Wi-Fi in the 21st century has allowed this connection to be wireless.

   Is the Internet dangerous?

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   The first computer networks were dedicated special-purpose systems such as SABRE (an airline reservation system) and AUTODIN I (a defense command-and-control system), both designed and implemented in the late 1950s and early 1960s. By the early 1960s computer manufacturers had begun to use semiconductor technology in commercial products, and both conventional batch-processing and time-sharing systems were in place in many large, technologically advanced companies. Time-sharing systems allowed a computer’s resources to be shared in rapid succession with multiple users, cycling through the queue of users so quickly that the computer appeared dedicated to each user’s tasks despite the existence of many others accessing the system “simultaneously.” This led to the notion of sharing computer resources (called host computers or simply hosts) over an entire network. Host-to-host interactions were envisioned, along with access to specialized resources (such as supercomputers and mass storage systems) and interactive access by remote users to the computational powers of time-sharing systems located elsewhere. These ideas were first realized in ARPANET, which established the first host-to-host network connection on October 29, 1969. It was created by the Advanced Research Projects Agency (ARPA) of the U.S. Department of Defense. ARPANET was one of the first general-purpose computer networks. It connected time-sharing computers at government-supported research sites, principally universities in the United States, and it soon became a critical piece of infrastructure for the computer science research community in the United States. Tools and applications—such as the simple mail transfer protocol (SMTP, commonly referred to as e-mail), for sending short messages, and the file transfer protocol (FTP), for longer transmissions—quickly emerged. In order to achieve cost-effective interactive communications between computers, which typically communicate in short bursts of data, ARPANET employed the new technology of packet switching. Packet switching takes large messages (or chunks of computer data) and breaks them into smaller, manageable pieces (known as packets) that can travel independently over any available circuit to the target destination, where the pieces are reassembled. Thus, unlike traditional voice communications, packet switching does not require a single dedicated circuit between each pair of users.

   Commercial packet networks were introduced in the 1970s, but these were designed principally to provide efficient access to remote computers by dedicated terminals. Briefly, they replaced long-distance modem connections by less-expensive “virtual” circuits over packet networks. In the United States, Telenet and Tymnet were two such packet networks. Neither supported host-to-host communications; in the 1970s this was still the province of the research networks, and it would remain so for many years.

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   What Do You Actually Know About the Internet?

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4. www.britannica.com › place › JapanJapan | History, Flag, Map, Population, & Facts | Britannica

   www.britannica.com › place › Japan

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   1 天前 · Japan. Japan, island country lying off the east coast of Asia. It consists of a great string of islands in a northeast-southwest arc that stretches for approximately 1,500 miles (2,400 km) through the western North Pacific Ocean. Nearly the entire land area is taken up by the country’s four main islands; from north to south these are Hokkaido ...

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5. www.britannica.com › topic › Japanese-languageJapanese language | Origin, Family, Alphabets, History, ...

   www.britannica.com › topic › Japanese-language

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   1 天前 · Japanese language, a language isolate (i.e., a language unrelated to any other language) and one of the world’s major languages, with more than 127 million speakers in the early 21st century.It is primarily spoken throughout the Japanese archipelago; there are also some 1.5 million Japanese immigrants and their descendants living abroad, mainly in North and South America, who have varying ...

6. www.britannica.com › topic › YouTubeYouTube | History, Founders, & Facts | Britannica

   www.britannica.com › topic › YouTube

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   2 天前 · YouTube, social media platform and website for sharing videos. It was registered on February 14, 2005, by Steve Chen, Chad Hurley, and Jawed Karim, three former employees of the American e-commerce company PayPal. They had the idea that ordinary people would enjoy sharing their “home videos.”. The company is headquartered in San Bruno ...

7. www.britannica.com › place › JapanJapan - Politics, Economy, Society | Britannica

   www.britannica.com › place › Japan

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   Japan - Politics, Economy, Society: Japan’s constitution was promulgated in 1946 and came into force in 1947, superseding the Meiji Constitution of 1889. It differs from the earlier document in two fundamental ways: the principle of sovereignty and the stated aim of maintaining Japan as a peaceful and democratic country in perpetuity. The emperor, rather than being the embodiment of all ...