TY - JOUR TI - Knowledge Graphs AB - In this article, we provide a comprehensive introduction to knowledge graphs, which have recently garnered significant attention from both industry and academia in scenarios that require exploiting diverse, dynamic, large-scale collections of data. After some opening remarks, we motivate and contrast various graph-based data models, as well as languages used to query and validate knowledge graphs. We explain how knowledge can be represented and extracted using a combination of deductive and inductive techniques. We conclude with high-level future research directions for knowledge graphs. DO - http://dx.doi.org/10.1145/3447772 SP - 1 EP - 37 UR - https://dl.acm.org/doi/pdf/10.1145/3447772 PY - 2021-01-01 JO - ACM Computing Surveys AU - Hogan, Aidan AU - Blomqvist, Eva AU - Cochez, Michael AU - de Melo, Gerard AU - Gutierrez, Claudio AU - Kirrane, Sabrina AU - Labra Gayo, José Emilio AU - Navigli, Roberto AU - Neumaier, Sebastian AU - Ngonga Ngomo, Axel-Cyrille AU - Polleres, Axel AU - Rashid, Sabbir M. AU - Rula, Anisa AU - Schmelzeisen, Lukas AU - Sequeda, Juan AU - Staab, Steffen AU - Zimmermann, Antoine ER -