Since the year 2000, the rapid development of educational technology and internet technology has brought significant attention to e-learning. Many studies have focused on understanding how to enhance learners' experiences and promote deeper engagement with learning content through e-learning to achieve better learning outcomes. Subsequently, from early 2020 over the span of the next three years, due to the impact of the COVID-19 pandemic, governments across many countries and regions implemented policies such as "Classes Suspended but Learning Continues," by conducting teaching and learning online. This has led to significant attention to e-learning by the academic and educational communities. Consequently, during these years, many studies on e-learning in the context of the pandemic have been published. However, as we enter the post-pandemic era, physical learning spaces are no longer restricted, and people have gained new insights into e-learning based on their experiences during the pandemic. Additionally, in the context of the ongoing digital transformation of education, it is also necessary to further explore e-learning topics in the era of Education 4.0. In summary, this book compiles the latest research findings on e-learning, helping readers to understand the e-learning research outcomes of scholars from different countries and regions.