Yii2 is a high performance, component-based PHP framework for rapidly developing modern Web applications.

The name Yii means "simple and evolutionary" in Chinese. It can also be thought of as an acronym for Yes It Is! Yii2 is a generic Web programming framework, meaning that it can be used for developing all kinds of Web applications using PHP.

Because of its component-based architecture and sophisticated caching support, it is especially suitable for developing large-scale applications such as portals, forums, content management systems (CMS), e-commerce projects, RESTful Web services, and so on.