The reason you use nails rather than screws is that nails bend, screws do not. As the framing shifts (and it will because nature) the nails will bend and allow the boards to remain attached as they shift.
Screws have the advantage of not backing out. So at right angles (think a deck board attached to the joist) they are preferred. Lateral force will, however, easily snap them. But for framing they are probably a code violation.
Screws have the advantage of not backing out. So at right angles (think a deck board attached to the joist) they are preferred. Lateral force will, however, easily snap them. But for framing they are probably a code violation.