There are many folders inside the Zend project, some of the important one’s are highlighted below :

Application	Contains the core application code. You can find all the controllers, models, and views of any application here.
library	Contains Zend Framework library files. I recommend placing all third-party source code here.
test	Contains unit test cases for the controllers. PHP unit is used.
Public	Contains the .htaccess and index.php files. I recommend placing all application CSS, JavaScript, images, and any static content here.
.zfproject.xml	File created by Zend_Tool to identify project.
application/controller	All controllers for the application should be placed here.
application/views	All helpers and views for the application should be placed here.
application/models	All models for the application should be placed here.
application/configs	All config files for the application should be placed here.
Bootstrap.php	Bootstrap.php file used to initialize components for the application.