Confusion with Mysql and Mysqli

<?php
	//using mysqli_connect. it is about dead nowadays
	$link = mysql_connect("localhost", "root", "");
	mysql_select_db("test", $link);

	$result = mysql_query("SELECT * FROM user", $link);
	//always try to use if condition for skipping errors
	if($result)
	{
		$num_rows = mysql_num_rows($result); 
		//it will not mysqli_num_rows
		//mysqli_num_rows will be used at time of using mysqli class
		echo $num_rows." Row";

	}

	?>
	
	<br/>
	<?php

		//using mysqli class. this is the best.
		$link = new mysqli("localhost", "root", "","test");
		if($link)
		{
			$result = $link->query("SELECT * FROM user");
			//always try to use if condition for skipping errors
			if($result)
			{
				$num_rows = $result->num_rows; 
				echo $num_rows." Row";

			}
		}

		


	?>