A backlink is a link from another domain to your site. It can help crawlers discover a page and pass signals about its topic, popularity or trustworthiness.
What is a backlink?
When an industry site links to your study, both the reader and the search engine learn why the source is useful. What makes it valuable is mainly the linking site and where the link sits on the page.
When it helps and when it hurts
The helpful kind is usually an editorial link from a relevant page that has its own audience and a reason to point to you. Google can simply ignore a random directory or automated spam.
The risky ones are links built mainly to manipulate rankings: link farms, paid networks or large-scale exchanges. Paid partnerships need the right attribute, for example sponsored.
Backlinks vs. internal links
Backlinks come from other domains, and you don't fully control them. Internal linking connects your own pages and helps navigation, crawling and the distribution of importance.
Both layers only make sense in a relevant context. A link should exist because it gives the user a useful next step. Building it to hit a count misses the point.
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