One Of the important aspects of Digital Marketing is understanding how your customers are finding you. Google Analytics have categories indicating how people found your site. Channels in Google are high level categories.
Referral - Traffic generated by user clicking on links from other websites, obviously excluding all the search engines.
Direct - Traffic generated directly through them typing the URL and also indicates people who clicked on the links from their bookmarks/favorites, un-tagged links within emails, or links from documents that don't include tracking variables (such as PDFs or Word documents).
Paid - Traffic generated through Pay Per Click campaigns.
Organic - Traffic through un-paid search results. Website listings on search engines, like Google.
social - Traffic generated through social networks. Like - Facebook, Twitter, Pinterest etc. depending upon the social platforms you are active on.
There are more -
E-mail - Traffic generated through links clicked in e-mail messages you send.
Display - Traffic generated from display advertisements, such as Google AdWords re-marketing campaign.
Affiliates - Traffic due to affiliate marketing
If you do Good SEO on your website your chances of getting traffic from all these sources is high.