For many years,webcam videos, sex, girls, public Adobe Flash was synonymous with animation on the web, browser games, and interactive websites. In 2011, the Flash Player plug-in was installed on 99% of desktop browsers in the Western world. One decade later, no modern web browser supports Flash outside of China.
In the 1990s, the internet was growing rapidly, and web browsers could not keep up with the pace of new file types that were designed to be shared over it. That led to the development of plug-ins: small apps that weren't designed to work independently, but add functions to the browser, like browser extensions do today.
Video plug-ins such as Apple QuickTime and the Windows Media Player showed video content that was made of individual frames, somewhat similar to how animated GIFs work, but with the added capability of showing some of those frames while the rest were downloading, and adding compression to improve loading speed at the expense of quality.
In the era of dial-up modems, internet video was either of low resolution, despairingly slow to load, or both. In that kind of context, interactive videos that loaded quickly and fully utilized the resolution of every screen looked like a miracle. This is the story of how a big part of the early web culture was formed.