If your toilet is plugged it will act in one of these two ways. The water will not go down at all and will overflow onto the floor when flushed. Or it will rise to the top of the bowl and swirl down slowly after a flush, often taking two or three flushes to get rid of solids and paper. The toilet almost always plugs in one of two places as noted by 'A'. Either some foreign object cannot make the bend at the top of the trap and becomes lodged there or it will make it around but won't go through the hole at the bottom of the toilet to the drain.
Most people think a plunger is a simple tool and they know how to use one.
This will cause there to be nothing but water between your plunger and the clog. No air that can compress causing there to be less pressure exerted on the plug. To get the water to this level if the bowl is plugged completely, remove the tank lid and lift the flapper by hand while watching the level in the bowl. When the water comes near the top, start plunging. Plunge back and forth as hard and as fast as you can for about six or eight repititions.