We can use several types of tags to define the start and end of PHP code. I have illustrated “few” of them that worked for me. The first one is basic echo with No tags, so it will just output the echo.
[php]echo "No Tags"
The second one is the most commonly used tag in PHP. It is the widely accepted standard.
<?php echo "This is the most commonly used tag" ?>
The third , is used very frequently , (Haven’t used this in WordPress though)
<? echo " Another tag "?>
And the last, is the old style (familiar with javacript declarations)
echo "this is php using script language"