Backlinks have been a major ranking factor with search engines for some time now and there is no sign this is likely to change.
Search engines have developed ways to measure all the links from other sites linking to yours to help decide how to rank your pages.
They can understand several factors including popularity and trust.
For example,
You could have created the most amazing site on the web, but if no one is talking about you, mentioning you and linking to you this will be perceived as unpopular so don’t expect to rank for much if anything at all.
Websites with high levels of trust and authority are normally large corporations and trusted news outlets. Being mentioned on one of these sites with a link will go a long way in Google’s eyes as they will start to take notice as you are effectively friends with the big players.
Not all links are treated equally, some links will give more benefit than others to your site. Care should also be taken when building links as they can even be toxic, so best to use a professional link builder who can weed out the good from the bad.
Link building has become big business over the years with many people claiming they can deliver amazing links and guarantee rankings which is completely false and should be avoided at all costs.