Timeline of the Internet: From ARPANET to Today

The internet's ancestor was ARPANET, a network funded by ARPA, a research agency of the US Department of Defense. Its purpose was to let scientists at different universities share computers and information. A popular story says it was built to survive a nuclear war, but the history written by internet pioneers for the Internet Society calls that a false rumour.

ARPANET used packet switching: a message is chopped into small packets that travel separately and are put back together at the other end. The internet still works this way today, whether you are streaming a cricket match or sending a photo.

On 29 October 1969, a student programmer in Leonard Kleinrock's lab at UCLA tried to log in to a computer at the Stanford Research Institute (SRI) in California. He typed "L" and "O" and then the system crashed. So the first message ever sent over ARPANET was simply "LO". By the end of 1969, four host computers were connected.

In 1972, Ray Tomlinson at the company BBN wrote the first basic email software, and ARPANET was shown to the public for the first time at a conference that October.

During the 1970s, many separate computer networks appeared, and they could not easily talk to one another. Vint Cerf and Bob Kahn designed a shared set of rules, TCP/IP, that lets any network connect to any other.

On 1 January 1983, every computer on ARPANET switched over to TCP/IP on a single day. That "network of networks" is what we now call the internet. In April 1995, the US government stopped funding the main NSFNET backbone, and commercial companies took over running the network.

The internet and the web are not the same thing. The internet is the network; the web is a way of publishing linked pages on top of it.

In March 1989, British scientist Tim Berners-Lee, working at CERN near Geneva, proposed a system for sharing information through linked documents. By Christmas 1990 he had defined its three building blocks, HTML, HTTP and URLs, and had the first web server and browser running at info.cern.ch. In August 1991 he announced the software to the wider internet, and on 30 April 1993 CERN put the web into the public domain so anyone could use it free of charge.

On 15 August 1995, India's Independence Day, the government-owned VSNL (Videsh Sanchar Nigam Limited) launched the country's first internet service open to the public. It started in Delhi, Bombay, Calcutta, Madras and Pune, using slow dial-up connections over telephone lines. Getting online meant a screeching modem and a lot of patience.

According to the International Telecommunication Union (ITU), about 6 billion people, roughly 74 per cent of the world's population, were using the internet in 2025. The gap is still large: around 94 per cent of people in high-income countries are online, compared with only 23 per cent in low-income countries.