Incoming link from the high profile sites is consider as quality back link they improve your authority of the sites.

Quality backlinks comes from reputable, high quality and relevant niche sites. Whether it would be a nofollow or dofollow link.

The incoming links to your website are backlinks.

Quality backlink improves your ranking position in the search engines. Getting a backlink from high PR sites will helps to achieve a good position in Google.

These are back links that adds value to your website

It have to be unique links

It is backlink that links to your website using keyword pharse.