Why are backlinks so important in SEO?

From the perspective of SEO, there is a difference between backlinks and quality backlinks. For Google search, random backlinks do not offer any help. Google assesses the quality of the backlinks present on a webpage with the relevancy found in the content of both the web pages. The higher is the relevance between the original content and backlink content, the greater becomes the quality of the backlinks. Quality backlinks bring more referral traffic to a website/blog, and most importantly will improve the ranking of a webpage.

Back link is regarded as vote of relevance. The problem is that webmasters have abused it, but major search engines have ways of detecting link spammers. Good backlinks help you rank well in search engines mostly in Google.