>>611254
>lowest cost
Nah. It's the polar opposite. Anything painted in camo always costs more.
The main differences in "military" hardware and "civillian" hardware are:
-What it is allowed to do.
-What the safety factors are.
What it is allowed to do is simple to answer: the military uses certain encryption modes and keys, which simple civillian tools are not built to use. Not because it's impossible for something that isn't painted green to use them, but because they are not allowed to employ these technologies. Another example are removed restrictions, such as the maximum difference in position the GPS will allow before shutting down (a restriction put in place to make it less likely that someone builds a GPS guided bomb/missile/whatever using civillian parts). Such restrictions don't apply to military hardware. The producer simply has to state that the parts they are producing are for military purposes only, and only sell them to the military, and then they can do whatever.
What the safety factors are is a little more tricky, since it's not uniform at all and depends a lot on the actual hardware in question. For those who never heard the term before (I am translating from my German knowledge, so the vocabulary might be wrong): a safety factor is a factor by which the maximum amount of force, current, torque or whatever else value is multiplied that the part or the entire machine-system has to withstand. If you want a plane to fly even at 20m/s crosswinds you design it in a way that it will fly even at 30 m/s (20x1.5=30)
Your car for example has a safety factor of 2 for most of it's systems; the engine, the doors, the windows etc.
Some systems require extra safeties, like the seat-belts (x3) and some require less, like the AC (x1.5 as far as I know).
Different areas of engineering use a different base safety factors: Civilian air-planes use x1.5, space-vessels and rockets use x1.2 to x1.1 in some areas, factory machines use x2 or even x2.5, some buildings use x3 etc.
Depending on what area your hardware will be used in, there will be different safety factors. The military safety factors are all over the place. Fighters have lower safety factors than civilian air-craft to keep them light, cheap and agile, but they are expected to take much higher loads because of the maneuvers they are expected to make. Tanks use ridiculously high safety factors, simply because the engine has the power necessary to move the extra weight, and it's a vehicle that expects to get shot at anyways. Naval safety factors a whole nother thing and depend even on what type of waters you expect the vessel to operate in (ponds, lakes, rivers, coastal waters, inland sea, high seas…)
Normal electrical hardware safety factors are a specific area themselves, and it requires an actual electric-hardware engineer to give a truly educated look at that. They also depend on what area the electrical component is used in (aboard a space ship, or in your car). Military electrical hardware is even more complex of a topic.
The takeaway from all this is: Unless you have a specific use scenario nobody can list the differences between a normal civilian parts and military parts. In some situations it might be light light and day, and in others the military might use civilian hardware, and in yet other circumstances civilian hardware even surpasses military hardware in most areas because the military hasn't come around to modernizing it's equipment.