The Dortmund Data Bank (DDB) is a collection of scientific data related to compounds and materials. It was created in 1965 and contains information about physical and chemical properties of over 1 million organic and inorganic compounds, and hundreds of materials like polymers and zeolites. This data is collected from several sources like experiments and simulations. All this data is stored in a database so that scientists can access it and use it to study physical and chemical properties of substances. This makes it easier for scientists to do research and find new solutions to real-world problems.