This is the directory structure you will end up with following the instructions in the Installation Guide.
|-- /app |-- /bootstrap |-- /config |-- /database |-- /public | |-- /assets |-- /resources | |-- /assets | |-- /lang | |-- /views |-- /storage |-- /vendor
app- contains your own namespaced application code
bootstrap- initialisation files including path configuration and loading of other core files
database- contains the database migrations (updates to database in each version) as well as sqlite files (if used).
public- should be the only directory that is publically accessible, i.e. the web document root.
resources/views- the location of the html views (overwriting from Doorstep default views)
storage- storage location for various files including cache, feed files, sessions, files, and media.
vendor- composer directory to store and load contains the main source code of Doorstep and third party libraries and frameworks