Re: nails or screws?
Your question is a little vaque -----
screws have by far better holding power than nails ---- use of adhesives is always desiarable for extra strength.
However, if you are asking about cabinet work you wouldn't use glues or nails in floating panels . In many cases glue is used for joints and held in place with nails while the glue sets ---- or clamped instead of nailed.
Screws wouldn't be used unless they were located in places that are hidden from view.
"" an ounce of perception -- a pound of obscure "