Chances are that you have dozens of 1/4" screwdriver bits in your tool cache. Some will be Phillips and some will probably be Pozidrive bits. What's "Pozidrive" you ask? Read the Wikipedia excerpt below to learn the difference between these two designs.
Using either screwdriver form in the other screw form can cause problems as discussed in the last paragraph of the Wiki quote. In order to keep things separated, I use a bronze Sharpie to color the tips of all the Pozidrive drivers. The photograph below shows a Pozidrive on the left and an ordinary Phillips driver on the right.
Quote from Wikipedia article entitled "List of Screw Drives"
The Pozidriv is an improved version of the Phillips screw drive. Pozidriv was jointly patented by the Phillips Screw Company and American Screw Company. The name is thought to be a portmanteau of the words "positive" and "drive." Its advantage over Phillips drives is its decreased likelihood to cam out, which allows greater torque to be applied. In ANSI standards, it is referred to as "Type IA." It is very similar to, and essentially compatible with, the Supadriv screw drive.
Pozidriv drive bits are often designated by the letters "PZ" plus a size code of 0, 1, 2, 3, 4 or 5 (by order of increasing size); the numerical bit size codes do not necessarily correspond to nominal screw size numbers.
Attempting to use a Phillips screwdriver bit is likely to cause damage because the design difference between them is fairly significant even though at first glance they appear to be very similar. A Phillips driver has an angle on the flanks, a pointed tip and rounded corners. The Pozidriv screwdrivers have straight sided flanks, a blunt tip and additional smaller ribs at 45° to the main slots. The Pozidriv was designed specifically to allow much greater torque to be applied because of its more positive engagement.
The Pozidriv screws are visually distinguishable from Phillips by a set of radial indentations (or "tick marks") set at 45° from the main cross recess on the head of the screw. The manufacturing process for Pozidriv screwdriver bits is slightly more complex. The Phillips driver has four simple slots cut into it, whereas in the Pozidriv each slot is the result of two machining processes at right angles. The result of this is that the arms of the cross are parallel-sided with the Pozidriv, and tapered with the Phillips.
The chief disadvantage of Pozidriv screws is that they are visually quite similar to Phillips; thus many people are unaware of the difference and/or do not own the correct drivers for them, and often use an incorrect screwdriver. This results in difficulty with removing the screw and damage to the recess and/or driver, often rendering any subsequent use of a correct screwdriver unsatisfactory. Phillips screwdrivers will loosely fit in and turn Pozidriv screws, but will cam out if enough torque is applied, potentially damaging the screw head and or driver. Because the drive wings on a Pozidriv screwdriver are square edged, their fit in a Phillips screw head is even worse, so they are more likely to slip or tear out the screw head.