Let's compare 2 examples of code

The old-school method based on HTML is still implemented today by many companies:

Here is the bloated HTML code you can still read on many sites:

<table width="500" cellspacing="0" cellpadding="0" border="1" bordercolor="#000000" align="left"> <tr><td width="100%"> <font face="arial, helvetica, sans-serif" size="4" color="#888866"><span class="header"> <b>Register online</b></span></font><td></tr> </table>

And here is what this code produces on the screen:

Register online

 

 

The same thing written in structural XHTML:

The code (to be compared to the above code):

<h3>Register online</h3>

And the result on the screen:

Register online

Even if you are new to coding practices, you can see that the result is the same but the second code is much more concise and to the point. The end result is light-weight pages that download more quickly to your browser and whose maintenance is much shorter.