This is the number of visits to your website from unique URLs, not including your own employees. A higher number of website visits means more people are landing on your site. This traffic is acknowledged by Google (and other search engines) as an indication of your website’s authority. As a result, your website starts ranking higher for keywords you’re targeting. One way of getting more visitors to your website is by promoting it extensively on social media.
SEO is hugely important to ensuring that your site shows up in the search results for the keywords and phrases most relevant to your business. Let's say you sell gourmet cupcakes. If someone searches for "gourmet cupcakes," your website should show up, right? What do you think might happen if the phrase "gourmet cupcakes" is nowhere to be found in your title tag, on-page content, or even in your product descriptions? As you might have guessed, the answer is "nothing."