Organic Search is visitors who reach you by Googling or using another search engine which Google recognizes as a real search engine — mostly Bing and its second string, Yahoo. People using other search engines like DuckDuckGo or sites which are now commonly used as search engines but which have other purposes, like Pinterest, will show up in Referral traffic and in the case of Pinterest, in Social. If you have a good, well-optimized website, Organic Search will usually be your most frequent source. At our lab site, we do nothing to encourage other sources, so Organic Search is absolutely the top.
This is the number of views that you can test each month on your website.It's up to you how you choose to use them, either by allocating all the views to one test or to multiple test, either on one page or on multiple pages. If you have selected the 10.000 tested views plan and you run an experiment on your category page which is viewed 7000 times per month, then at the end of the month 7000 is what you'll be counted as tested views quota.