Street names and numbers, businesses etc. associated with those streets, and stuff like that. Say you have some idea, like...you want to build a tool that aids

Street names and numbers, businesses etc. associated with those streets, and stuff like that. Say you have some idea, like...you want to build a tool that aids cargo ships, fishing vessels, or other vessels with the most efficient route (with respect to fuel usage) between ports. The first thing you need to do, is to map all ports. There may not exist any such pre-compiled list, but you could always use map tools like OSM to scan all coastlines, and see if there are any associated ports, docks, etc. there. Then when you find one, you save the location, name, and other info you can find. This is pure brute force, and can naturally be quite expensive for the providers. But since you're a dinky one-man startup with zero funds, that's what you do - you can't be bothered with searching through hundreds (to thousands) of lists in various formats, from various sites, that may contain the info you're looking for.