When any visitors come from direct search engine is called organic traffic.
When any visitors come from another site is called referral traffic.
When any visitors come from social media site is called social traffic.
When any visitors come from email link or direct URL in browser is called direct traffic.
Organic traffic is the best of all and it has a great value in Google. Currently my blog is getting more than 62% organic traffic according to Google analytic. You also can increase your organic traffic easily following bellow trick.
How to Get Organic Visitors