Morphs change the shape of all the elements of a figure or an expression: nose, eyes, head, hips, bewbs, etc ;). It's what's used to make that one model look like many different people or to make the figure smile, blink, open it's mouth. In Poser, there are dials in the body part properties panel that when changed, makes the morph get stronger or weaker. You can make your own unique characters that way. The characters that you see for purchase are normally a figure with the morph packs whos dials have been spun into a unique figure. They also normally come with a skin texture as well.

Laurie