Pop riveting is used to join two pieces of sheet metal through a blind hole. The head of the rivet is put into the holes in the pieces of sheet metal and the mandrel is pushed inside the nozzle of the rivet gun. The levers on the rivet gun are then squeezed and the mandrel is pulled out. This pulls the head of the rivet inwards, causing it to expand outwards. The mandrel will the snap off and the rivet will be stuck in place in the hole.
A crimping tool is used to deform one material onto another. For example, a metal tube onto electrical wire
The two parts are put together, put into the appropriate part of the crimping tool and the levers are pressed
A buttress thread can withstand a lot of force in one direction. The flat faces of the screw can hold the weight of something/hold something in position.
For example, this type of screw thread is commonly used in a vice as once it is tightened, it can hold the force exerted by the vice. It will not come loose, as the pressure from holding a material rests on the flat faces of the thread. It is also commonly used in vertical applications, such as lifting machines such as forklifts.
Quick and easy to, doesn't require skilled worker, temporary joint can be undone, very practical in a lot of cases
Can come loose, some cases need a permanent joint, requires space/clearance for the nut and bolt to go, bulky
Duno what you need to know really, guess it's kinda obvious
Just remember it is a type of mechanical joining