Network literacy is important as our world becomes increasingly connected through networks. A basic understanding of how networks work and their benefits and limitations is needed for all people living in today's networked world. Networks exist in every aspect of life, from communication systems and social networks to biological and economic networks. Understanding networks can help reveal patterns and allow comparisons across different types of systems. While networks are ubiquitous, the study of networks is currently absent from educational systems. This document provides an introduction to network literacy through seven essential concepts.