This document discusses concepts related to identity formation and communities of practice. It covers: 1. Communities of practice are formed through mutual engagement, joint enterprise, and shared repertoire. They create meaning and boundaries. 2. Identity is negotiated through participation and non-participation in communities. It involves modes of belonging and is a dual process of identification and negotiability. 3. Social processes like experience, membership, learning trajectories, and local/global belonging shape identity formation. Practice and identity are related but distinct concepts.