#1 Slider - This is the mechanical part of the zipper and has a Y shaped channel that moves along the rows of teeth and meshes or separates the opposing teeth.
#2 Pull - This is a "handle" for the slider. It gives you something to hold to operate the slider.
#3 Tape - This is the material that has the teeth embedded into it. It comes in many different widths and lengths.
#4 Teeth - The teeth on one side mesh with the teeth on the other to fasten the zipper.
There is a unique type of zipper that has a pair of slider/pull sets. These are called two-way or double-separating zippers. You will find them most often on jackets.
The top slider/pull allows you to unzip the jacket from the neckline down. The bottom slider/pull allows you to unzip the jacket from the hemline up. This allows you to keep the jacket fastened, but still allow additional movement and ventilation by partially releasing the zipper.