The book "Reasoning Web. Reasoning and the Web in the Big Data Era" offers a comprehensive introduction to the latest developments in the field of the semantic web and linked data, particularly in the context of Big Data. The lecture notes presented here are from the 10th Reasoning Web Summer School, which took place in 2014 in Athens. The content is aimed at students and professionals who wish to engage with the fundamental techniques of reasoning and their application to large datasets. The lectures cover both theoretical and practical aspects and provide valuable insights into the challenges and opportunities arising from the processing and analysis of Big Data. The authors, including renowned experts in their field, present current research findings and innovative approaches that are significant for the development of applications in the area of the semantic web.