This brief from the Global Science of Learning Education Network (GSoLEN) offers a clear, concise definition of the Science of Learning. It explores how insights from neuroscience, psychology, education, and other disciplines come together to explain how the brain changes and adapts throughout life, and how culture, relationships, well-being, and environment shape that process. It also considers how this evidence can reach every classroom, teacher, and learner, and introduces GSoLEN, a global community of more than 900 members across 70+ countries working to make that happen.