Output code

The Views PHP field contains a section labelled Output code where you can create output to be displayed by the field. The content starts in HTML mode and you can add PHP using the PHP element.

The following example prints a node title from a node row.
<?php print $row->title; ?>

The following example prints a node title from a node row within a heading.
<h2><?php print $row->title; ?></h2>

$value

Views PHP has a section to generate a value that will be returned to Views. The Output section follows the Value section and, in my test, the Output section shows the value from the Value section as $value. I can display $value in HTML using code such as the following.

<div style="background-color: #ccccff;"><?php print $value; ?></div>

The value is also added to $row as $row->php, something you can display as follows.
<div style="background-color: #ccffcc;"><?php print $row->php; ?></div>