static method meaning in laravel code example

Example 1: static function model laravel

public static function isOpen($week)
{
    return (new static)::where('week', $week)->first();
}

Example 2: laravel call a static function

namespace App\Library;

class Utilities {

 //added new user
 public static function doBeforeTask() {
  // ... you business logic.
 }
}

// then do this in your controller 
Utilities::doBeforeTask();