Link building is important because it determines how Google ranks web pages. Google states:
In general, webmasters can improve the rank of their sites by increasing the number of high-quality sites that link to their pages.
Let us say that we own a website promoting wind turbines. We are competing with another manufacturer of wind turbines. Google will look at link popularity when determining our page's rank.
With the links we build and the website that links to us helps Google to determine the following things.
How authoritative and trustable the website is?
How big the website is and how often people talk about it?
Does the website have any relevant awards?
Where can we rank the website in the search results?
Think it simple= a link is just a <a> tag in terms of website design. Any website that allows us to create a link and is relevant to our sources is a good source of backlink to you.
By link building with quality backlinks, these site metrics will increase, giving your site a beneficial 'healthy status'. 4. Drive Referral Traffic. Once your link gets a good footing on relevant sites, you'll likely see an increase in traffic to your site.