Backlinks play an important role in the search engine algorithm, SEO and your overall strategy for developing your website.
The easiest way to think about backlinks would be to talk about websites.
For example, John is a blogger and writes a very interesting article about a sporting event.
Another blogger, Samantha, refers to John's article when he shares his point of view. Since he writes on the topic on his well-known online magazine site, this creates a link after John's publication.
Since the online magazine is popular, many other sites refer to its article. This increases the authority of the online magazine and John's article also gets a valuable backlink from a reputable site.
Basically, it's a victory.
Here some examples of backlinks