The scissors jack uses a long bolt to squeeze together two arms that then lift the car.
A scissor jack uses a fine threaded screw and mechanical advantage to lift a vehicle. A hydraulic jack uses hydraulic fluid, a pump, and a cylinder to lift the car.
Under it sounds right. If you look at the top of your jack (scissor jack), and look under the side of your car, between the front and rear wheels, near the tire you want to jack up, there should be a notch that the top of your jack was made for. There's probably a label on the spare tire cover with detailed instructions.
The same material as your car or mine.
It will be made of many components the casing material will not matter much.
A car chassis is made of heavy boxed steel, stamped steel or aluminum.
well that all depends on what kind of jack you are using. and if it is the proper jack for the vehicle. floor jacks are the simplest of jacks then the scissor jacks are the most common but i don't trust them much. however either one are simple enough to use try to find the instructions for installing and using the jack properly.
Safety glass, same as your car or mine.
Underneath each door there are two notches on what looks like the siding, but is actually part of the frame of the car. Assuming you have a scissor jack, you would place it right where the notches are. There are four spots total with notches.