Which multimedia format is most commonly used for creating interactive web content?

The selection of Flash as the answer highlights its historical significance in developing interactive web content. Flash was widely adopted for creating animations, games, and interactive features on websites due to its ability to incorporate vector graphics, audio, and video into a cohesive experience. This multimedia format allowed developers to create engaging interfaces that could respond to user actions, making it particularly popular for web applications and online entertainment during its peak usage.

In contrast, the other formats serve different purposes. GIFs, while capable of animations, lack the interactivity and complexity that Flash provides. PDFs are designed primarily for document sharing and do not support interactive web features. JPEGs are standard image formats that focus on static images and do not offer the interactive capabilities seen with Flash. Thus, Flash stands out as the most suitable format for creating fully interactive web content, shaping the way developers approached multimedia on the internet.