Question on yii and general theory?

Question

Yii

Hello. Guys, there was a question.
For my development, I want to make a simple site on the YII framework. I chose it thanks to a different review and decided to start with it in order to understand what it is, what delights you can experience in development. Then, if it is successfully done, then I will try on symphony2.
Now a question.
1. Why frameworks, why can't you write everything by hand and from scratch? How useful is a framework?
2. How to get cookieValidationKey in yii? I don't understand where it comes from.
3. Difference between basic and advanced template. As I understand it, advanced has the ability to frontend and backend, but this cannot be done on basic?
4. If there is already a ready-made template engine in yii or it is not needed there, is everything in pure php?

Answer 1

1) Much faster. And you make websites instead of delving into the architecture and trying to constantly improve your code, which has a mediocre relation to websites
2) write it yourself in the configs, read about it in the chapter on configuring / installing Yii
3) You can, but it's rather conditional. Start with a basic template, it will be enough for a start, and when you understand the basic concepts and master the framework, you can deal with advanced. However, you can go the third way and create yourself a basic template that suits you in everything.
4) Usually templates are written in pure PHP (this allows you to conveniently connect regular widgets and methods), but there are libraries for integrating Smarty and Twig if necessary

Answer 2

1. www.phptherightway.com/#frameworks