A collection of written works that delve into the systematic study of the structure and behavior of the physical and natural world, often through observation and experiment. This category also includes books that provide practical advice or instruction on hardware and do-it-yourself projects, emphasizing the application of scientific knowledge for practical purposes. It encompasses the broad field of technology, focusing on the design, construction, and use of machinery or equipment, as well as the techniques, skills, and processes used in the production of goods or services.