A template tag is code that instructs WordPress to “do” or “get” something. Like in header.php we will use the tag bloginfo(‘name’) to get “Site Title” from wp-options table which is set in Setting > General at WordPress dashboard.
The the_title() template tag is used to display the post title.
wp_list_cats() is for display categories.
get_header() for getting header.
get_sidebar() for display the sidebar on page.
get_footer() for get the footer content on page.
