Direct/unknown
in the Referrers box shows you how many people visited your site without a referrer set. That could mean they came directly to your site (i.e. they typed in your URL), came from an email or app, or a referrer simply wasn’t set (some sites do this, and no analytics software can control it).
Note that we only started recording Directs/unknown data in March 18, 2021, so if you’re viewing data that includes pre-March 18, 2021 data, it won’t include this data. And if you view a date range that includes date before March 18 and after, the sum of the referrer visitors won’t add up to the total visitors as we don’t have data prior to that date (so we only show the data we have).