Yii Framwork or Yii ?
Yii framework is a free, open-source Web application development framework written in PHP5 that promotes clean, DRY design and encourages rapid development. It works to streamline your application development and helps to ensure an extremely efficient extensible, and maintainable end product.
Check more detail in here Yii introduce and history site.

Why choose Yii framework ?

Actually, this is my experiences in working with framework. I used to have a chance to try CodeIgniter and  Zend Framework 1.0. When I use Yii, I feel like this framework is easy to learn. They support almost tools we need. There are some unique from Yii.
  • Gii code generater. Gii can create model, controller, forms
  • CRUID is a special tool. Just need the database, it create all attribute include create/update/delete function.
  • Form handle, active field. This mean Yii help us validation form’s field.
  • Translation for multiple languages website
  • Yii framework shop module
  • ….. (Something that I don’t know).

Performance Yii Framework