IF THE CONTENT OF THE PAGE IS...

is_home()

is_front_page()

is_404()

is_search()

is_date()

is_author()

is_category()is_category()

is_tag()

is_tax()

is_archive()

is_single()

is_attachment()

is_page() custom-template.php page-slug.php page-id.php page.php

tag-slug.php tag-id.php tag.php

category-slug.php category-id.php category.php archive.php index.php

author-nicename.php author-id.php author.php

date.php

search.php

404.php

front-page.php

home.php

taxonomy-taxonomy-term.php taxonomy-taxonomy.php taxonomy.php

MIME_type.php attachment.php

single-posttype.php

archive-posttype.php

single.php

what pageare we on? what page template will be used by default?

Note the “fallback” system... if any template isn’t present, WordPress simply uses the next in line until it gets to index.php

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