iTunesConnect review beta test vs AppStore

All,

When I submit my app for review in itunesconnect, I can submit it for beta testing as well for the App Store.

1) are these linked to each other?
2) what if I submit it for the both? Can this be active parallel?
3) what if I submit it only for beta testing? If test are ok, will the review for the App Store be shorter than 'normal'?