Im new at Yii and studying it i've seen that it works by passing in a explicit way the URL that represents controller and actions (as CakePHP also does).
it is known as "route"
it is widely used in MVC based frameworks.
but if i wanna use a Friendly URL?
is there any way to implement it without extra coding?
Friendly URL's is a very efficient ways to improve what we call of SEO.
Your concern is reasonable. Creating too many routing rules in Yii (or any other frameworks) will degrade your application performance. This is really a trade-off between performance and functionality.
The benefit of using URL rules in Yii is that it offers you two-way URL management: URL parsing and URL creation. Apache rewriting is only for URL parsing, so are most other frameworks.
As a result, Yii developers can always create URLs in the same form: createUrl($route, $params). And the generated URLs can be changed easily to different SEO-friendly forms by changing the URL rules. They no longer need to hardcode URLs in their code.