Backlink is one of the 4 most important factors in SEO, only after content (Content is King, Link is Queen). It can be simply said that backlinks are links from other websites to your website, it is an indispensable part and plays an important position in increasing the ranking of your website before your fastidious Google friend.
Backlink is the return link, backlink means the link returned from another website to your website. More specifically, you or a user places a backlink on a referring website based on characters such as anchor text or a full link and when the user clicks on that link, it will lead to your website.