What do you mean, "What is it"?
The first in the Power Macintosh line, the 4400 was released in November 1996. It had a 160 or 200MHz PowerPC processor and supported a massive 160MB of RAM.
It's neat in that it's never been opened. There was an unopened Apple ][gs floating around a while back. I'd love to send in the warrantee card on one of those, just to see what Apple would have to say about getting a postcard with
"Apple Computer Inc." on it.