Please somebody tell me what is Steam? and what is steambox ? I hear that a lot of gamefaqs now but have no idea what either of the two are.
Steam is an PC game service developed by Valve. Through the service, people can buy games, trade in-game items, and a lot of other things. Go to the Wikipedia page if you want to know more:
The Steam Machine (What it's properly called) is a PC that's running on a Linux OS that's designed to work like a console. The OS for the Steam Machine is called the Steam OS. What the Steam OS is is Gabe Newell's response to Windows 8 since he was upset with how Windows 8 handled PC games (from what I heard).
To put it simply the Steam Machine is a console that's designed to be a PC. In a way, it's sort of the opposite of the PS4 and XB1.