Usually needed for displaying the stylesheet directory for use in file paths, put lots of other good uses as well
Format
<?php bloginfo('stylesheet_directory'); ?>
Complete List – follow the same format as above
name = Testpilot
description = Just another WordPress blog
admin_email = admin@example
url = https://example/home
wpurl = https://example/home/wp
stylesheet_directory = https://example/home/wp/wp-content/themes/child-theme
stylesheet_url = https://example/home/wp/wp-content/themes/child-theme/style.css
template_directory = https://example/home/wp/wp-content/themes/parent-theme
template_url = https://example/home/wp/wp-content/themes/parent-theme
atom_url = https://example/home/feed/atom
rss2_url = https://example/home/feed
rss_url = https://example/home/feed/rss
pingback_url = https://example/home/wp/xmlrpc.php
rdf_url = https://example/home/feed/rdf
comments_atom_url = https://example/home/comments/feed/atom
comments_rss2_url = https://example/home/comments/feed
charset = UTF-8
html_type = text/html
language = en-US
text_direction = ltr
version = 3.1