Say I have a post called Hello World in Wordpress and I'm directly viewing this page, how would I go about finding the category of "Hello World" and displaying it?
Use get_the_category()
like this:
<?php
foreach((get_the_category()) as $category) {
echo $category->cat_name . ' ';
}
?>
It returns a list because a post can have more than one category.
The documentation also explains how to do this from outside the loop.