Visitors who come to your website through a certain channel or source. The 7 most typical ways traffic arrives at your site is:

• Organic: Visitors who arrive on your website "organically," by clicking search results, through a search engine, like Google or Bing, that led to your website. Users who arrive organically have not clicked a paid ad.
• Direct: Users who arrive at your site directly, usually by typing in your website URL.
• Referral: Visitors who click to your website from a link shown on another site. For example, a partner site may post a link recommending and leading to your website.
• Paid: Visitors who arrive at your site by clicking a paid ad/search result or Pay Per Click (PPC) campaign or another type of online ad leading to your website.
• Social:  Visitors who arrive on your website from a social network like Facebook, LinkedIn, Twitter, or Instagram.
• Affiliate: Users arriving on your after clicking a link from a third-party marketer (affiliate) who may receive compensation for promoting and selling your website brand, products, or services.
• Existing email list: A list of email addresses gathered from previous visitors or customers who have signed up to receive communication from your site.