Search engines use links to discover new web pages they can then use in their search results and to determine how well a page should rank in their results.
Once search engines have crawled pages on the web, they can extract their content and add it to their indexes.
This helps them to resolve if they feel a page is of sufficient quality to be ranked well for relevant keywords.
The search engines look at the number of links pointing to the page with content from external websites, and the quality of those external websites.
Link building will involve outreach to other relevant websites and blogs in your industry. This outreach will be related to the promotion of something that you’ve just created including a piece of content, infographics, or more. The value of a link isn’t just about SEO — it’s about customers; the links are placed on your website in front of people certainly interested in what you do. The customers are going to be aware of who you are and what you do if they click through.
When combined with strong technical SEO foundations, insightful on-page SEO, quality content, and a perfect user experience, link building can be extremely effective at driving plenty of organic traffic.