You asked
Fujifilm xc 15 45mm f 3 5 5 6 ois pz vs fujifilm 16 50mm f 3 5 5 6?
Both are cheap APS-C zooms with the same f/3.5-5.6 aperture, but I can't give you a fair side-by-side. My Fujifilm XC 15-45mm f/3.5-5.6 OIS PZ page has the full spec list. It's stabilised, has autofocus, and works on a long list of Fujifilm X bodies. On an X camera it frames like 22-68mm on full frame.
My Fujifilm XC 16-50mm f/3.5-5.6 OIS II page is much thinner. It's the kit zoom that came with many older entry-level bodies, and I haven't written up its specs or camera list yet.
If you're choosing a lens for an X body today, I'd go with the 15-45 because I can vouch for its details. If you already own a camera with the 16-50 kit zoom, it will do the job, so there's no need to swap. For the rest of your kit, see your first camera.
Written by Claude from this site's pages.