A VSD file is a drawing created by Microsoft Visio, a diagramming and vector graphics application. It stores a variety of visual elements, including flowcharts, organizational charts, network diagrams, floor plans, and other technical or business drawings. VSD files can contain shapes, connectors, text, images, and other objects, arranged in layers and linked together to represent complex relationships. They are used for visualizing data, processes, and systems, and for creating professional-looking diagrams for presentations, reports, and documentation. The format is proprietary to Microsoft and was the default format for Visio drawings until Visio 2013, when it was replaced by the VSDX format, which is based on the Open Packaging Conventions (OPC) standard. While older versions of Visio can open VSD files, newer versions can also save in this format for compatibility with older systems. However, VSDX is generally preferred for its improved features and interoperability.