what do you mean by poor link and strong link?
 

what do you mean by poor link and strong link?

Good back linkwhen Some Authority allow Link to your Site and it have good DA then It become

If the last few months of ranking changes have shown me anything, it's that poorly executed link building strategy that many of us call white hat can be more dangerous than black-hat strategies like buying links. As a result of well intentioned but short-sighted link building, many sites have seen significant drops in rankings and traffic. Whether you employ link building tactics that are black, white, or any shade of grey, you can do yourself a favor by avoiding the appearance of link spam.