In Yii, cookie is an object of 'yii\web\Cookie'. 'yii\web\Request' and 'yii\web\Response' maintain a collection of cookies via the property named cookies.variable.
A session is a way to store information (in variables) to be used across multiple pages for individual users request. 'yii\web\Session' instance is used to access the session application component.
Yii2.0 framework having default application components and it is giving different type services. This post will help you to create custom yii2.0 component, how to configure the component and how to call the component.
High performance is always a primary goal of Yii 1.x and Yii2.0. Yii 2 inherits the main spirit behind Yii for being a simple, fast and highly extensible PHP framework.
We can install Yii in two ways, using Composer or downloading an archive file. The former is the preferred way as it allows you to install new extensions or update Yii by running a single command.