Column in HTML5

How to specify column properties in HTML5?

By using <col> tag we can specify the column properties of table, each column with in a colgroup in HTML5. <col> tag is used only when the values of each column are different.

tr - To create a Row
td - To create a column

    <style>
        .colClass
        {
            background-color:red;
            font-size:x-large;
        }
    </style>

<body>
    <table>
        <colgroup>
            <col />
            <col class="colClass" />            
        </colgroup>
        <tr>
            <td>1</td>
            <td style="color:yellow;background-color:green;">2</td>
        </tr>
        <tr>
            <td>2</td>
            <td>3</td>
        </tr>
        <tr>
            <td>3</td>
            <td>4</td>
        </tr>
    </table>
</body>