MYSQLI_ASSOC and MYSQLI_NUM

// mysqli_fetch_array($query)                          [General and simple Process]
while ($row = mysqli_fetch_array($query)) {
        ?>
        <tr>
            <td><?php echo $row['id']; ?></td>
            <td><?php echo $row['name']; ?></td>
            <td><?php echo $row['roll']; ?></td>
            <td><?php echo $row['created_date']; ?></td>
        </tr>
        <?php
    }

// MYSQLI_ASSOC                                    [index names will be same as user defined]
while ($row = mysqli_fetch_array($query,MYSQLI_ASSOC)) {
        ?>
        <tr>
            <td><?php echo $row['id']; ?></td>
            <td><?php echo $row['name']; ?></td>
            <td><?php echo $row['roll']; ?></td>
            <td><?php echo $row['created_date']; ?></td>
        </tr>
        <?php
    }

// MYSQLI_NUM                                      [index names will be change as 0 , 1 , 2 , 3 , n ]
while ($row = mysqli_fetch_array($query,MYSQLI_NUM)) {
        ?>
        <tr>
            <td><?php echo $row['0']; ?></td>
            <td><?php echo $row['1']; ?></td>
            <td><?php echo $row['2']; ?></td>
            <td><?php echo $row['3']; ?></td>
        </tr>
        <?php
    }

// mysqli_fetch_assoc($query)                     [index names will be same as user defined]
while ($row = mysqli_fetch_assoc($query)) {
        ?>
        <tr>
            <td><?php echo $row['id']; ?></td>
            <td><?php echo $row['name']; ?></td>
            <td><?php echo $row['roll']; ?></td>
            <td><?php echo $row['created_date']; ?></td>
        </tr>
        <?php
    }