The document discusses material property databases and their features. It provides examples of several popular open source and paid databases, including MatWeb, MakeItFrom, MatDat, MatMatch, MaterialConnexion, Total Materia, Knovel, Altair, Jahm, and others. It summarizes the key features of each database, such as providing material properties, comparisons, experimental data, models, search tools, and links to suppliers. It also provides screenshots of search pages and examples of material property data from several databases.