I am new learner on Laravel.
I am using Laravel 5.3.But I want Use Bootstrap css and Js. But Laravel have default app.css and app.js. Hare app.css actually Bootstrap CSS and also app.js work like Bootstarp js. But can i delete app.js and app.css and can i use custom version Bootstrap CSS & JS ?
So I need to know why we will be use this two files ?
You can delete them, read the following lines:
CSS
Laravel Elixir provides a clean, expressive API over compiling SASS or Less, which are extensions of plain CSS that add variables, mixins, and other powerful features that make working with CSS much more enjoyable.
In this document, we will briefly discuss CSS compilation in general; however, you should consult the full Laravel Elixir documentation for more information on compiling SASS or Less.
JavaScript
Laravel does not require you to use a specific JavaScript framework or library to build your applications. In fact, you don't have to use JavaScript at all. However, Laravel does include some basic scaffolding to make it easier to get started writing modern JavaScript using the Vue library. Vue provides an expressive API for building robust JavaScript applications using components.
Laravel default CSS and JS files are safe to remove.
However, these styles will be used in the following places by default, so please be taken care of it.
If you are using custom themes or your own styles, you can use Laravel Elixer to compile them and which will create app.css for style files and app.js for javascript related files.