What does this ( -> ) do? (RESOLVED)

[lleemon]

I saw the following code and am wondering what the following is happening when you have ->?

function infoBoxContents($contents) { 
global $css_class; 
$this->table_cellpadding = '3'; 
$this->table_parameters = 'class="'.$css_class.'"'; 
$info_box_contents = array(); 
...... 

Thanks in advance.