what is the suitable version of w8 for my pc?

[harsh2009]

window 8 launched of 26 oct. 2012. well the are three version
1. window 8
2. window 8 pro
3. window 8 rtm
and i am really confuse what are these.
these are the final beta versions i think but i cant figure out what version i install.
and one more thing if you can tell me about window 8 genuine activation.
you are working on it?
thanks for you reply

my configuration is
64 bit core 2 dual
2 gb ram
non touch monitor
nvidia 210 gc
thanks.