Explain Letters Numbers

Hello.

G means it has integrated graphics.
P means it has "Video Sideport Memory"
M means it is Mini-ATX
T means it has DDR3

I found this easily using Google and Google is not just for me so there is not really a sufficient excuse for why you couldn't find it. Anyway these are the two threads I sourced information from:

http://www.tomshardware.com/forum/268102-30-what-number...
http://www.xpmediacentre.com.au/community/archive/t-412...

Hope that helped.