So I live in a part of the UK that has plenty of woodland, heathland, hills and countryside, near the end of the Southwest Coast Path, which has some fairly tricky bits to negotiate. Some routes follow roads for a bit before plunging back into overgrown footpaths or gravelly hills. I've never quite worked out which parts of these come under walking, and which hiking. It doesn't seem to be as clearly defined over here as in, say, the US. Especially when we have terms like hill- or fell-walking (though I don't think my hills qualify for those terms).
I want to mark off various hiking challenges, but I want a reasonably consistent benchmark that allows me to say "yes, that was hiking x miles, I can tick that off" or "no, that was just walking through a bunch of boggy fields".