Can someone explain what Stage3D is?

I have no idea what it is and whenever I try to google it, I can’t really understand how the companies explain it. How is it better than it’s competitors? Just want to understand what’s so good about this and what makes it better than it’s competitors.
Answer #1
Stage 3D, previously codenamed “Molehill,” is a new method/model of 2D and 3D rendering developed by Adobe and supported with a new Stage3D API—a set of low-level GPU-accelerated APIs enabling advanced 2D and 3D capabilities across multiple screens and devices (desktop, mobile, and TV) through the runtimes. These APIs provide advanced 2D and 3D developers with the flexibility to leverage GPU hardware acceleration for significant performance gains in video game development.
Adobe Flash Player previously rendered thousands of non z-buffered triangles at approximately 30 Hz. With the new Stage3D APIs, you can expect hundreds of thousands of z-buffered triangles to be rendered at HD resolution in full screen at around 60 Hz. Using the new Stage3D APIs in Flash Player and Adobe AIR will make it possible to deliver sophisticated 3D game development experiences across almost every computer and device connected to the Internet.