A backlink in SEO (search engine optimization) is a link from one website to another. When a website links to another website, it’s like a vote of confidence in the content on the receiving site. In SEO, high-quality backlinks from reputable websites can help improve a site’s search engine ranking, as search engines view backlinks as a signal of the website’s authority and relevance. However, it’s important to note that not all backlinks are created equal, and some low-quality backlinks can actually harm a site’s ranking. Therefore, it’s important to focus on building high-quality, relevant backlinks from reputable websites in order to improve SEO efforts.