Question about news sync

[hmmm]

Ok, I am sure this is a very newb question but here goes. I can set my News app to sync or not sync under Menu>Settings>Accounts and Sync. I can also change the updating of the app from manual to 30 minutes, 1 hour etc.

My question is what is the difference between having the app auto sync and having the app auto update? What happens when you set it to auto update but turn off the sync? Or when you turn sync on but auto update to manual?

Thanks.