Google loves backlinks very much, they are one of the core parts of their original search formula that ultimately won the search wars and is the standard today. Backlinks are a vouching of one website to another.
It is one of the best ways for them to determine what your business is about and serve those results up to people looking online through the search engine. The higher the amount of other sites vouching for your site (backlinks) will determine how high the site comes up in search.
There are other factors, the most important is the quality and amount of content on your website. Especially content that has the same keywords or keyword phrase you want to rank for.
Let’s talk about keyword phrases and how they work with backlinks. If someone needs a plumber in Las Vegas, they will most likely search “plumbers las vegas” or a variable like “plumbers vegas” / “plumbers henderson nv” etc. If a backlink on a quality website located in vegas has the link text (meaning the words you click on) as the same “plumber las vegas” it will pull up in search higher than a site that didn’t have that link (if both sites were equal in all other ways). So backlinks become extremely important.
But it’s not just getting links from anywhere that helps, it helps the most to get links from local business websites and industry websites. Irrelevant websites or websites located in foreign countries do not benefit as much and can even hurt SEO with backlinks (especially bad websites like adult content or spam linking to your site).