link_tag([$href = ''[, $rel = 'stylesheet'[, $type = 'text/css'[, $title = ''[, $media = ''[, $index_page = FALSE]]]]]]) 
Parameters:
$href (string) – What are we linking to 
$rel (string) – Relation type 
$type (string) – Type of the related document 
$title (string) – Link title 
$media (string) – Media type 
$index_page (bool) – Whether to treat $src as a routed URI string  Returns:
HTML link tag  Return type:
string  
Lets you create HTML <link /> tags. This is useful for style