Regarding Cloud Computing

Hi,

Can someone clarify the below for me

Is Para virtualization and Operating system based Virtualization same ?
Similarly is Full Virtualization and Hardware based Virtualization same ?

Also which type of Virtualization can have VM's with similar OS type eg Windows/Linux and which type of Virtualization can have VM's with different OS type i.e 1 VM with Windows and another with Linux .

Please help to clarify the above.

Thanks
Somnath