Topical Authority
Topical authority is a reputation for knowing one subject well.
When a site covers a topic deeply and reliably, search engines and AI start treating it as a go-to source.
It is not domain authority. Domain authority is a general score for a site's links and age. Topical authority is about one subject and how well you cover it.
Search engines and AI look at how fully you cover the topic, who you are linked to, whether trusted sources cite you, and whether you stay on topic.
You build it with pages that connect, not one-off posts. A common way is a pillar page that links out to smaller articles on each part of the topic.