system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 why we need to have multiple types of screwdrivers/screws and not just one all-encompassing type?

I understand some places will have less common screws so people can't steal things without the right tools, but all in all, what's the major purpose being screws varying from phillips head/flat head/hex?
gpt
All screw types have their own advantages and disadvantages.

* Slot head: It was the first one, invented back in the time where screws were often still hand made, and it was the simplest screw head to build.

* Phillips: Specifically designed to push the screwdriver out of the screw("cam out") if the screw is already tight. This was done to prevent damaging the screw or the workpiece by overtightening.

* Pozidrive: Looks very similar to Phillips, but doesn't cam out as much. Often used where you need more force(torque) to drive the screw than a Phillips screw would allow.

* Hex: Allows you to exert even more torque to tighten the screws, but you won't get any protection from over tightening the screw. The hex wrench is also very simple and cheap to manufacture, which is why it's used so often for Ikea and other furniture.

* Torx: Like Hex it allows you to apply a lot of torque. The contact between the Torx screw and driver is better than with a Hex screw, which means the torque is distributed more evenly over the contact area, which means less wear than Hex and more torque can be applied.


We could continue this list even further, but you get the idea: Every screw head has certain strengths and had its reason to be designed. Some screw heads could be considered obsolete now, but are still used because they're good enough and the tools and production lines already exist.