Generally speaking, Poser is not a modeling program but more of a rendering system. Most Poser addon characters are actually constructed outside and then imported into Poser. You do setup a bone system in Poser so you can bend body parts. Then you build a scene with the characters and props much like building a scene in a movie. You can animate objects using key frame animations, and manipuate lights and cameras in the scene. Once you have a scene built you render it to an image file or in the case of an animation you can make an AVI/MPG digital movie type file. Like so many other programs nowadays, there are tons of plugins and addons, even one called Mimic so you can make a characters mouth move like it is talking in time with a wav file. Here is a simple render
Actually, it is not all that bad. Yes, by FS standards. you would have poor frame rates if you were to use the figure there. My system is a couple of years old. AMD 1.3ghz, 512mb PC133 memory, Win2kPro, Riva TNT2 Ultra w/32mb memory. Poser4 Pro, for the most part, runs fairly smooth, but Poser 5 is pretty piggy.