Is bondage/bdsm a fetish...?

[LD]

As far as categorizing porn sites? I think of fetish as unusual things that turn people on. Spanking, smoking, panties maybe...but I think of bondage/bdsm as being a category all to itself. I've seen it both ways, just wondering how others view it.

And maybe someone could explain the difference in bondage and bdsm while you're at it...