virtual technology

I don't understand what is virtual technology.Does anyone know about it????

I came to know about it from one of thefriendsand now I want to know about it .He said the following :

I want to enable VT (Virtualization Technology) on my computer but no options are available within the BIOS (version A11). I see future BIOS updates on the XPS700 have enabled this feature and I would greatly appreciate this also to be made available on the XPS600.