ช่วยอธิบายทีคับ คอมเม้นให้หน่อย แปลว่าอะไรบ้างคับ วานโปรเทพๆช่วยคอมเม้นที

<?
include('config.php');
class ResultSet {
	private $result;
	
	public function __construct($result) {
		$this->result = $result;
	}
	
	public function next() {
		return mysql_fetch_array($this->result);
	}
	
	public function size() {
		return mysql_num_rows($this->result);
	}
}

class MySQL {
	//	Attribute
	private $connect;
	private $host = 'localhost';
	private $mysql_username = 'root';
	private $mysql_password = '123'; 
	private $mysql_db		= 'classified_bank';
	

	public function __construct() {
		$this->connect = mysql_connect($this->host,$this->mysql_username,$this->mysql_password) or die(mysql_error());
		
		mysql_query("SET NAMES UTF8");
		
		mysql_select_db($this->mysql_db, $this->connect);
	}

	public function query($sql) {
		$ret = mysql_query($sql);
		
		if (!$ret) {
			die(mysql_error());
		}
		
		return new ResultSet($ret);
	}
	
		public function querynoreturn($sql) {
		$ret = mysql_query($sql);
		
			if (!$ret) {
				die(mysql_error());
			}

		}
		public function Size($sql) {
		$ret = mysql_query($sql);
		
		
			if (!$ret) {
				die(mysql_error());
			}else{
			return mysql_num_rows($ret);	
			}

		}
		
	
	public function getLastInsertId() {
		return mysql_insert_id();
	}

	public function __destruct() {
		if ($this->connect) {
			mysql_close($this->connect);
		}
	}
	
	public function query_insert($sql) {
		$ret = mysql_query($sql);
		
			if (!$ret) {
				die(mysql_error());
			}

		}
}
?>