The acronym CGNS stands for the "CFD General Notation System". It is a software library designed to store and exchange data related to computational fluid dynamics. CGNS has a variety of synonyms depending on the context, such as software framework, data model, file format, and pre- and post-processing system. It is widely used in the aerodynamics and aerospace industries, as well as in various scientific fields such as chemical and process engineering. Many computational fluid dynamics software packages support the CGNS data format, enabling users to use it as an efficient data transfer interface between different CFD programs.