The FireBee is a new Atari-compatible computer. Ataris and Atari-Clones are special computers with their own hard & software. They aren't PC's, Mac's nor Amiga compatible.
A FireBee is similar to an Atari Falcon and works very much like that. It will run most of the Atari compatible software that would run on a Falcon. Different to older Ataris and their clones, the FireBee is a modern computer that supports almost everything you'd expect from a today's machine, like USB ports, Ethernet, DVI-I monitor connector, SD-card reader and more.
This brand-new Atari compatible is not cheap, but much like the current Amiga computers, if you're worried about the price, you're probably not the intended audience. Note that even though the order page says "pre-order", I think that's a typo - you can order them directly from the Swiss company that makes them, too.
I love that people and companies are passionate enough to keep developing, building, and selling machines like this - it's a vital effort to keep platforms alive well into the future.