Also called Auto Campaigns, these are simple campaigns that are mostly controlled by Amazon.
Automatic campaigns are campaigns that contain no keywords, but rather specific Automatic Targeting Types. Their main search term matching functionality is controlled by Amazon. When using an Auto Campaign, Amazon will show your ad for search terms it has determined are relevant to you based upon several factors, including your front end and back end listing.
Search term data from automatic campaigns can be a valuable source of research information for building out manual campaigns.