positional aggressive active solid defensive ,,, chess engines

hi every one

what is the difference between the playing styles of the chess engines like :


1-Aggressive
2-Active
3-Solid
4-Defensive
5-Positional
6-tactical
7-Human-like ( human style )

and as you think put the chess engines you knows with the appropriate playing style like :

Stockfish :
Komodo :
Houdini :
Shredder :
Zappa :
and allll other chess engines


thanks

Take a look at these articles:

Chess Styles
http://www.uschessleague.com/ChessStyles.html

Chess engines' playing styles
http://www.chessbase.com/newsdetail.asp?newsid=4357

Adopting a Style of Play
http://www.ez-net.com/~mephisto/Adopting%20a%20Style%20of%20Play.html