The Opendelight reinforces the correct development paradigm through different prescriptions and architectural procedures. Having a clear directory and file structure is one of them. This creates a separation of business logic from UI design on one hand, and user development from Opendelight's upgrades and Opendelight IDE on the other. After installation, the Opendelight creates the following directory structure:

1. /login1 : This directory contains files structure as the following:
/index.php - Login index file. /sso.php - Single Sign-On configuration file.
1. /osf1 : This directory contains all files of the Opendelight IDE. You can even delete this directory after completing development, and that will not affect the running of your application in any way. Different types of files are stored in their own subdirectories like the following: /data - data files
/ide - controller files
/install - installation files
/lib - The scripts and classes provided by the Opendelight are stored in this directory.
Please note that the files in this directory will be updated if you do upgrades of the Opendelight in the future with newer versions.

2. /model1 : All files of Model or business logic are stored here. The Model classes or application classes are stored in a subdirectory /class, and independent scripts are stored in /script
/thirdparty - external files
/view - the Opendelight IDE view parts files

3. /pub1 : This directory contains all folders and files related to CSS, fonts, images, and js files. Different types of files are stored in their own subdirectories like the following: /css - CSS files
/fonts - Font files
/images - Image files
/js - Javascript files

The Opendelight also provides a few key files in the application root that are critical for the application running. The following table provides details of each of these files:

The Opendelight files in the application root Description of files and their usage
/changelog If you enable Lifestream on the Opendelight IDE, the application will generate a log every time the application is accessed. This log information is stored as text files in this directory.
/index.php The cache files created by the application are stored in this directory. This includes static files created by the application beforehand and served to the client-side for improving application performance and reducing the load on the server.
/load.osf.php This directory meant to store external scripts that are to be added to an application being developed by the Opendelight.
/load.view.php This directory is the storage of uploaded files to the application. You can save uploaded files in /// form or in any other form as per the convenience of application requirements.

1. Directories with respect to the application root