routes can be handled in modules, what’s the impact?
app.all handles all methods for a provided routeRoute path: /users/:userId/books/:bookId
Request URL: http://localhost:3000/users/34/books/8989
req.params: { "userId": "34", "bookId": "8989" }
router is in express 4.0, acts as a smaller express appapp.use('/foo', router)