Large applications are often divided into front-end and back-end (or even more ends) depending on the target user groups. The front-end should be used by common users, while the back-end mainly the administrators or staff members. The two ends usually have dramatically different appearance, even though they may share a lot of code underneath. In this tutorial, we describe a way of organizing directories of the code for both ends. *Note, by no means
 
 
> Note: The directory organization described isn this directory organization a standard that fits for all scenariotutorial is meant to serve as a referential implementation. It is not a standard. Yii offers complete freedom for you to organize your directories, according to your needs.*

To start with, we give out the directory organization as follows,

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wwwroot/