Defining Stanza features and assigning them a priority enables two-way communication between your infrastructure and your front end. When you label front end components with a Stanza feature, the UI toolkit can do smart things like disabling or removing low priority features to keep high priority ones working under load. When a request has a feature label, it is treated in a prioritized way by Stanza guards - so higher priority requests get preference for speed and serviceability. Even if you don't want to get that fancy, you can embed features in your UI and push custom messages to customers, directly in the relevant UI component!
Features are capabilities of software, and their constituent traffic flows through backend services - like 'product search', 'checkout' or 'settings'