What is the basic building block when organizing around value?

 Agile Teams are the basic building block when organizing around value in SAFe. They are cross-functional, self-organizing, and empowered to deliver value in short iterations. They are aligned to a common mission and vision through the Agile Release Train (ART), which is a long-lived team of Agile Teams that delivers value streams. Agile Teams apply Scrum, Kanban, and XP practices to collaborate and deliver solutions that meet customer needs and provide business value. References: Agile Teams, Agile Release Trains, Exam Study Guide: SP (6.0) - SAFe Practitioner