buy download or package + mobile intenet

Hiya all I'm currently thinking of purchasing mobile broadband for home usage i.e the USB dongles but how do I get internet security software on my laptop which doesnt have a dvd/cd player?

I read on norton website there is a option to buy download or package - what are these and the difference between the two?

 

If i purchase a downloadable version - can I install this on other pcs (i.e. the ones which have 3 user licence?)

 

What about the standard cd that comes in the box if you purchase off the shelf - will i be able to create a bootable cd (off another pc which has a cd rewriter)?