A feature team is “is a long-lived, cross-functional, cross-component team that completes many end-to-end customer features—one by one.”
Traditional development teams are often organised as component teams, where the team will work on a component which then needs to integrated with one (often many) components developed by other teams. Feature Teams on the other hand are organised to deliver the complete end-to-end feature.
Feature teams are an essential element to scaling up agile development. Without a feature team structure (but instead, a component team organization—based on code ownership, combined with a single-function organization—analyst group, programmer group, testing group, …) your organization is likely to create numerous wastes and sub-optimizations that lead to a sequential (waterfall, …) development cycle. Feature teams structure resolves many of these wastes but also introduces change and challenges.
Where to lean more about Feature Teams
You can read more about feature teams and download the Feature Teams primer from www.featureteams.org. Mike Cohn has also written a nice article on the Benefits of Feature Teams.