This video, presented by Prof. Christoph Ellert (HES-SO), provides an introduction to hydrogen, its properties, occurrence, generation, storage, and usage. Hydrogen is the smallest and most abundant element in the universe, yet it is relatively rare in its pure form on Earth. It is commonly found in water and other bound molecules. The video covers hydrogen's physical and chemical characteristics, including its density, energy density, and the hydrogen bond. Valert also discusses various methods of generating hydrogen, such as electrolysis, and explores the idea of storing hydrogen underground. The video is part of a larger hydrogen course, with subsequent parts focusing on more detailed topics.