active) { Html::cssFile('@web/css/active.css'); } else { Html::cssFile('@web/css/inactive.css'); } ?>This code checks whether the data is active or inactive, and loads the corresponding CSS file accordingly. In conclusion, Yii\helpers\Html::cssFile() is a helper function in Yii framework that is used to add CSS files to web pages. It is a part of the yii\helpers\Html package library and is commonly used to add style to a web page.