Difference wood and deck screws
Most(all?) screws have a corrosion delaying treatment on them, what used to be considered outdoor decking screws are now constructions screws (the gold screws) due to the change in pressure treated wood chemicals. 

The corrosion delaying treatment on modern decking screws has been changed to accommodate ACQ treatment, which is significantly more corrosive than CCA (the old way to treat lumber). This is also why when building a deck you have to use hot dipped galvanized (HDG) bolts and brackets as opposed to electro plated zinc (the shiny ones). 

You'll notice on construction screw boxes a red circle with a bar across the letters ACQ, this means they are not suitable for pressure treated lumber as the chemicals with quickly corrode the sacrificial layer. 

As an aside, drywall screws are also heavily used in cabinet making because of their thin shafts, it removes the requirement of a pilot hole.