To understand containers, we must first review what segments are. Segments are categories that your visitors are assigned based on certain behaviors or attributes. This lets you focus on a specific segment in a specific way, and another segment in a different way, allowing for a higher level of targeted interaction. According to Adobe Experience League, segments can be based on:
Visitors based on attributes: browser type, device, number of visits, country, gender.
Visitors based on interactions: campaigns, keyword search, search engine.
Visitors based on exits and entries: visitors from Facebook, a defined landing page, referring domain.
Visitors based on custom variables: form field, defined categories, customer ID.
These segments are then further broken down into containers, which are based on a Visitor, Visits, and Hits. Knowing the difference of these three is very important, as it determines what is both included and excluded in the segment.
The Visitor container includes every visit and page view for visitors within a specified time frame. A segment at the Visitor level returns the page that meets the condition plus all other pages viewed by the visitor (and only constrained by defined date ranges). As the most broadly-defined container, reports generated at the Visitor container level will return page views across all visits and lets you generate a multi-visit analysis. Consequently, the Visitor container is the most susceptible to change based on defined date ranges.
Visitor containers can include values based on a visitor’s overall history:
Days Before First Purchase
Original Entry Page
Original Referring Domains
The Visit container lets you identify page interactions, campaigns, or conversions for a specific web session. The Visit container is the most commonly used container because it captures behaviors for the entire visit session once the rule is met and lets you define which visits you want to include or exclude in building and applying a segment. It can help you answer the question of how many visitors viewed the News and Sports section in the same visit? Or pages that attributed to a successful conversion to a sale?
Visit containers include values based on occurrence per visit:
Linearly allocated metrics
The Hit container defines which page hits you would like to include or exclude from a segment. It is the most narrow of the containers available to let you identify specific clicks and page view where a condition is true, letting you view a single tracking code, or isolate behavior within a particular section of your site. You may also want to pinpoint a specific value when an action occurs, such as the marketing channel when an order was placed.
Hit containers include values based single page breakdowns:
Merchandising eVars (in context of events)
This is just the tip of the iceberg with Containers and Segments. The Adobe Experience League offers a wealth of information to keep learning more and help you find answers to your questions. To learn more, take a look at the links below! And, special thanks to @brian_au