Feature is a unit of consumption of product functionality. Feature is developed by working on issues contributing to the feature and is made available to consumers as part of releases.
Feature can be used by activities. It may also define activities exemplifying use of the feature. Such activities may be referenced from journeys.
For example, “Cloud microservice code generator” may define an activity explaining how to generate a microservice code, put it source control, and initiate a first build. Then, this activity may be referenced from “Create a cloud application” journey.