Do we have a definition for how these should be used differently? City has a wiki entry and town doesn't; City also has ten times as many entries...
The city wiki gives the impression of what I've always had in the difference in their use in that a city is larger than a town, but that doesn't seem like something one could objectively define looking at a picture. So maybe they should just be aliases for one another?
or cathedrals, stuff that sticks up a good 3 or 4 stories above ground level
air/space/seaports
factories
warehouses
large roads
city skyline
City vs Town used to mean "cathedral + large town = city" (and cathedrals were always in large(-ish) towns), which has since changed to "large town with a more significant administration than "a mayor & small council" and recognition from the state as a city". Neither definitions are useful to danbooru, so instead we may as well use the 2 words for our own purposes.
Not quite sure what exactly to do with village and railway/tram. Obviously a village is smaller still than town with less infastructure, but where to draw the line? And certainly in contemporary Japan (or even 19th century Japan/Europe) railways and trams are hardly an indicator of the local urbanisation levels.