No matter what kind of server you are building (a RESTful one, as we plan to do, or any other kind), you'll have to deal with routing, and Node and Express together provide easy ways of doing this. 

Going back to our database from the Working with a database section in the previous chapter, in a RESTful fashion, we should provide the following routes, allowing for the given methods:

• /countries (GET to obtain the list of all countries, and POST to create a new country)
• /countries/someCountryId (GET to access a country, PUT to update one, and DELETE to delete one)
• /regions (GET to get all regions of all countries, POST to create a new region)
• /regions/someCountryId (GET to get all regions of a given country)
• /regions/someCountryId/someRegionId (GET to access a region, PUT to update one, DELETE to delete one)
• /cities (GET to get all cities – but we won't really want to allow this because of the resulting set size!—plus POST to create a new one)
• /cities/someCityId (GET to access a city, PUT to update one, and DELETE to delete a city)

You could also allow for extra parameters, for example, to allow paging a result set, or to enable some filtering, but what we care about now is setting up the routes. You could set up all of the necessary routes in the main file, as we have been doing in our short examples so far, but as you start adding more and more routes, some organization is needed to avoid ending up with a thousands-of-lines-long main file.