@yii- framework directory.
@app- base path of currently running application.
@common- common directory.
@frontend- frontend web application directory.
@backend- backend web application directory.
@console- console directory.
@runtime- runtime directory of currently running web application.
@vendor- Composer vendor directory.
@bower- vendor directory that contains the bower packages.
@npm- vendor directory that contains npm packages.
@web- base URL of currently running web application.
@webroot- web root directory of currently running web application.
The aliases specific to the directory structure of the advanced application
@console) are defined in