The dot-com bubble was a period in the late 1990s when the stock prices of internet-based companies soared to unrealistic levels. Investors were excited about the potential of the internet, leading to a surge in funding for many startups, often without solid business plans. This frenzy created a market where companies like Pets.com and Webvan saw their valuations skyrocket, even if they were not making profits. However, by 2000, the bubble burst, and many of these companies collapsed, leading to significant financial losses for investors. The aftermath taught valuable lessons about the importance of sustainable business models and cautious investing in the tech industry.