10 Questions You Should to Know about 12° Tapered Drill Bits

I guess I don't quite understand how to use these bits correctly.
If I hold the bit up against the applicable screw with the screw end even with the drill bit end the only amount of thread I see is just a small amount where the drill bit tapers. The rest of the drill bit is a larger diameter than the screw itself including the threads.
When I insert the screw into the drilled hole it drops down except for the previously noted protruding amount of thread surface length.(maybe 1/2"). In the photo it looks like the drill body is too big for the screw to me. Before these bits came didn't the diameter of the drill bit for the receiving wood part supposed to be the diameter of the screw shank?
Am I missing something?

In softer woods I use a non-tapering countersink drill and in hardwoods I use the tapering. I snapped a few screws off before I got the tapering set. The first set I bought were the Cheapies and as you could imagine, The drill bits snapped too. I'm not sure which brand I have now but cost more and haven't failed. JCB

I don't fully understand the question, but when using screws to assemble two workpieces, generally you would want a countersink and clearance hole in the upper piece and a "tap drill hole" in the lower piece. The reason for this is if the diameter of the hole in the upper piece is too small, the threads could bite into the material and jack the upper piece off the lower piece slightly before the threads grab in the lower piece. This would cause a gap in the assembly.

Make sense?

It's the type of screw you're trying to use, eh?

From McFeely's:

"Cut thread is oldest way of making screws. Cut thread uses a larger diameter wire and cuts material away to for the thread. Cut threads generally require use of tapered drill bits proper holding power. Rolled thread uses smaller wire and rolls the wire through dies to squeeze the threads onto the shaft. Rolled threads produce threads proud to the shank of the screw. These tend to hold better and can be used with a standard pilot hole drilled with a straight bit."