Twenty-five years ago, a British computer scientist named Tim Berners-Lee wrote a paper modestly titled: "Information Management: A Proposal".
That paper by Sir Tim - who has since been knighted - contained the idea that would ultimately become what we now know as the World Wide Web.
Make no mistake, the Internet had been around for years and military personnel and computer scientists had used it to transfer information and communicate.
But having a website or an address for each site - something we now take for granted - was a completely new concept.
Last year, the Internet was used by more than 2.7 billion people, or about 39 per cent of the world's population.
It has changed the way we communicate, work, learn, create and even laugh - "lol" - and will likely continue to change human behaviour as new developments arise.
Many people now cannot imagine life without the Internet.
People have "changed their lives around the technology", says Professor Ang Peng Hwa, director of the Singapore Internet Research Centre at Nanyang Technological University.
Living without the Internet would be akin to living without the MRT, he says. "You can, of course, but your life will not be the same."
But there weren't always that many people online.
Data from the International Telecommunication Union (ITU) - an agency of the United Nations - shows that in 2003, only 12.3 per cent of the world were using the Internet.
Access to cheaper computers is one reason for the rise in Internet adoption, says computer science professor David Evans from the University of Virginia.
Between 2003 and last year, he says, the cost of the computing power required to use the Internet fell by 100 times, making it more accessible.
Fixed-broadband access has also become cheaper, dropping 82 per cent from 2008 to 2012, according to the ITU.
Experts say the rise of Internet usage in developing countries has to do with education and awareness, as well as the increasing affordability of mobile phones.
Prof Ang points out that many of these countries have "feature phones", which are a step down from smartphones but allow users to access the Internet for e-mail or Facebook.
He cites China, India and Indonesia as drivers of the increased use of the Internet.
China's online population overtook that of the United States in 2009, he says, and the number of people online in India is expected to overtake those in the US in the next few quarters.
At the end of last June, there were 591 million Internet users in China, while in the US, there were around 255 million users last year.
Latest available numbers for India put the number of Internet users at 165 million in March last year.
In China, the spread of the Internet has led to a dramatic increase in e-commerce.
For example, Chinese online shopping site taobao.com has grown so big that there are Taobao villages with factories that make products mainly for sale on the site, says Prof Ang.
Meanwhile, Indonesia is seeing a boom in start-ups, many of which head to Singapore for financing.
But Internet penetration around the world remains uneven.
According to the World Bank, Singapore has the highest Internet penetration rate in South-east Asia, at 74.2 per cent in 2012, a vast difference from a developing country like Cambodia at 4.9 per cent penetration.
In the US, the figure was 81 per cent and people are increasingly dependent on the Internet.
A study released last month by the Pew Research Centre states that 53 per cent of Internet users in the US would find it "very hard" to give it up, compared with 38 per cent eight years ago.
The Pew study also shows that only 11 per cent of American Internet users said it would be hard to give up social media.
Says Associate Professor Coye Cheshire from the University of California Berkeley's School of Information: "While tweets and status updates may get a lot of popular attention at the moment, it is the more mundane acts of reading the news, searching for health information, transferring money, or finding an address that make the Internet so important to many American Internet users."
One of the more recent developments on the Internet is the introduction of new generic top-level domains or gTLDs - the segment of the domain name after the dot.
Internet users are familiar with .com, .org or .net but now, .actor, .diamond, and even .christmas are up for grabs.
The title of Sir Tim's 1989 paper may have been studiously neutral, but the ubiquity of the Internet in our lives today has provoked strong feelings about whether it has brought more harm or good.
One way of looking at it, says Prof Cheshire, is "as an infrastructure that provides a flow of data and information - just like other utilities provide flows of electricity, water or gas".
He adds that such resources "can be used to do many different things that might be valued as positive or negative, based on cultural, political and other social beliefs".
"The fact that data can be created, shared and consumed is not fundamentally controversial," he says.
Others point out that this ability to share information has been a huge boost to human interconnectedness and productivity.
For example, thousands of programmers working together on open-source projects created the code that runs on Android and iPhone devices.
"Such collaboration would not have been possible without the Internet," says Prof Evans.
But at the same time, this "means it can be used by evil people to find each other and work together more effectively also," he adds.
Some worry that the price we pay for this constant connectedness is real human interaction.
We have been in situations where someone is checking Facebook or Twitter on a mobile device instead of talking to the people there.
Last year, owners of a bar in Brazil thought of a novel solution to this.
They introduced "anti-texting" beer glasses, where the phone is needed to prop the glass up, preventing people from using their phones while at the bar.
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