I’ve tried using it over the years but I never liked it because there was no information. So last night I looked at my local city and there is almost no information at all. I spent a few hours last night adding buildings and restaurants and removing incorrect items. It was actually kind of fun and therapeutic and I plan to do more of it tonight. My girlfriend thinks it’s dumb and I’m wasting my time because Google maps and Apple maps and Bing maps exists but she just doesn’t understand open source.
Edit: Apologies, I just realized this question is not Linux specific.
Wiki has descriptions for the surface types, https://wiki.openstreetmap.org/wiki/Key:surface gravel seems to be general term that includes compacted gravel, I had to look up difference between dirt, ground and unpaved without text descriptions from the wiki that would have been impossible.