When a website links a web resource in its web page, it is called backlinks. A web resource can be a website, web page or web directory.
For example, here is a backlink from the site selectplugin.com, which added a link of our site for “Lazy Load for Images” plugin.
Backlinks are also known as inbound links, incoming links or one way links.
Google and other major search engines consider backlinks to be a ranking factor. Pages that have backlinks with a high number of backlinks have higher search engine rankings.