Laravel Pagination
https://laravel.com/docs/5.4/pagination
<?php
public function index()
{
// get parameter id if its present in url:
// admin
// admin/4
$videos = ( request()->id )
? Video::where('category_id', '=', request()->id )->paginate(10)
: Video::latest('created_at')->paginate(20) ;
// $videos = Video::latest('created_at')->paginate(20) ;
return view('admin.dashboard')->with('videos', $videos)
->with('categories', Category::all() ) ;
}