IELTS Reading: Matching Sentence Endings

The internet is the defining technological infrastructure of the modern era, yet its origins lie not in the commercial sector but in the military research priorities of the Cold War. The Advanced Research Projects Agency Network (ARPANET), funded by the United States Department of Defense, was the world's first packet-switching network. Packet switching — the technique of breaking data into discrete units that can travel independently across different network paths before being reassembled — was chosen over circuit switching because a packet-switched network could theoretically survive the destruction of any single node, making it more resilient in the event of nuclear attack. ARPANET first went live in 1969, connecting four university nodes in California and Utah. Initially, its use was restricted to academic and military institutions; the idea of a publicly accessible global network was still decades away. The theoretical foundations of the internet's data transfer protocols were established by Vint Cerf and Bob Kahn, who in 1974 published the Transmission Control Protocol (TCP) and Internet Protocol (IP) specifications — collectively TCP/IP — that form the basis of internet communications to this day. Their work defined how data should be packaged, addressed, routed, and received across interconnected networks. The transformation of the internet from an academic tool into a global public medium was achieved above all by the invention of the World Wide Web by the British computer scientist Tim Berners-Lee in 1989 at CERN. Berners-Lee proposed a system of hyperlinked documents accessible via standardised URLs and displayed by a browser — a concept he described as a 'web of information'. The first website went live in 1991. Critically, Berners-Lee chose not to patent the Web, making it freely available to the world. The Web was transformed from a text-based system used by academics into a popular mass medium largely by the development of graphical web browsers. The Mosaic browser, developed at the National Centre for Supercomputing Applications (NCSA) in 1993 by a team led by Marc Andreessen, was the first to display images inline with text and support multiple internet protocols. Mosaic's ease of use triggered exponential growth in web traffic and laid the foundation for the commercial web boom of the mid-to-late 1990s.