Backlinks allow your site to rank higher and succeed much faster, but not all backlinks are created equal. For the overall health of your website, it is imperative to know the difference.
What Is A Backlink?
A backlink is when someone else links to your site from an external source. For example, if you write a guest post on someone else’s website and there is a link within that post that leads back to your site, that is what is referred to as a backlink. More than that, a backlink is considered to be a vote of 
confidence. If someone allows you to have a link from their site to yours, then clearly your site must be trustworthy. But you still must be careful.
Google places a lot of importance on backlinks and it is vital to understand what separates the good from the bad.
What Defines Quality Backlink?
A quality backlink is when you get a backlink from a legitimate, respected website. It is a site with great content and that abides by Google’s standards. If you are receiving a backlink from a site that appears shady or that it is trying to “game” Google, then that can be harmful. Google will look at this shady site and will follow that link back to your site. Not only will they penalize the shady site, they will penalize you as well. Don’t let this happen. Carefully select the websites you choose for backlinks.
How to Obtain Quality Backlinks
Backlinks have so much importance to Google because they can be tough to obtain. They require effort on your part. One simple way, as mentioned above, is to guest post on respected sites. Find a site within your niche that is well known and pitch a guest post to them. Another easy way to get a backlink is by writing a press release. There are many press release sites out there you can use, but, again be careful to choose a respected one. By writing a press release you will get a backlink and your content will be in front of thousands of potential readers.
Getting quality backlinks all comes down to content. Writing for websites, writing press releases and writing your own quality content and promoting it are the most well-known and respected ways to get backlinks. By sharing quality content, Google will reward you.
Quality backlinks are considered to be the currency of the internet. The more you have, the richer you are.