What is Backlink? Definition and explanations
A backlink is a link pointing to your site from another domain. Search engines read it as a trust signal, but not all links are equal: what matters is the source site's authority, topical relevance and the editorial nature of the link. A bought or automated link may be ignored or even penalised — quality clearly outweighs quantity.
In one sentence
A backlink is an inbound link from another domain, read as a trust signal.