Dreamcast Collection happened in 360.
Dreamcast Collection was created on 2011-02-22.
There are no dreamcast emulators that will run dreamcast ROMs. The dreamcast is cd-based, so you can either download an emulator like Chankast, and use actual dreamcast CDs (you can get them for a couple of dollars/pounds) or download dreamcast ISOs
If you have Sonic Mega Collection Plus, then you can play it, or if you have a Sega Dreamcast. Those are the only two possibilities that I can think of.
The Dreamcast cannot emulate itself, however, it is possible to obtain a Dreamcast emulator for a PC. Various emulators, such as Chankast Alpha, exist.
No a Dreamcast game will not play on your computer but just putting the disc in there. You would have to play a dreamcast game on a dreamcast system.
Dreamcast BIOS dumps are not legally redistributable. You must dump them yourself from your own Dreamcast.
Tomodachi Collection happened in 2009.
The Sly Collection happened in 2010.
Sports Collection happened in 1996.
They can only play games that are designated for the dreamcast.
You only play Dreamcast games like Sonic Adventure on your Sega Dreamcast instead of Sega Saturn.
They stopped making Dreamcast Consoles in 2003.