This document provides an overview of networks and network leadership from the perspective of the Monitor Institute. It discusses how networks can accelerate social impact for non-profits and shares frameworks and tools for understanding networks. Key points include that networks allow for decentralized coordination, emergent solutions, and new technologies are enabling more collaborative approaches. Effective network leadership requires facilitating collective action, building connections, and nurturing self-organization with a network mindset. Tools like network mapping can help analyze network structure and flow.