Items are organized into three primary categories, these are:
AFA and AI categories are shared by all users, whereas items in RFY are only visible to a small subset of viners.
Items will usually circulate in Vine members' RFY for two weeks before moving to AFA or AI. Items rotate in and out of various RFYs anywhere from 1-24 hours, but most things sit in RFY all day and shuffle out overnight. There are many theories about how items are filtered into individual RFYs, but for the vast majority of people it seems completely random.
Products shipped & sold by Amazon show up in this tab. Their ETV is usually less than similar items in AI because they are sold by Amazon, and occasionally pet items that show up here are free (water fountains, food, & treats). If you've been put in "Vine Jail", this is the only visible tab.
Items sold by brands and third-parties. Most items are found here.