For Poser content like figures , props, poses, etc you install from the zip or exe installer to the Poser runtime.

For non-poser stuff in obj, 3ds, lwo you can use File, Import and load them into Poser. Anything loaded that way is a Prop and not movable without more work.

 

Poser file extensions are

cr2 - figure

pp2 - prop

pz2 - pose

hr2 - hair

fc2 - face

there is also a hand library , dont remember the extension

for each of these there is a compressed file form.  cr2 - crz

 

imports

obj -wavefront obj - standard poser file for geometry

lwo - lightwave version 5

3ds - old format for 3dsmax - all triangles