The VSD file format is a proprietary file format used by older versions of Microsoft Visio, a diagramming and vector graphics application. These files store drawings, diagrams, flowcharts, and other visual representations of data and processes. VSD files contain information about shapes, connectors, text, formatting, and other elements that make up the diagram. They are typically used for creating technical drawings, organizational charts, network diagrams, floor plans, and various other types of visual documentation. While VSD was the primary format for Visio drawings for many years, it has largely been superseded by the newer VSDX format, which is based on the Open Packaging Conventions (OPC) standard and uses XML for data storage. Opening and editing VSD files generally requires Microsoft Visio or a compatible viewer. Due to its legacy status, support for VSD files in newer software and online platforms may be limited, making conversion to a more modern format like VSDX or a standard vector graphics format like SVG sometimes necessary for broader compatibility and accessibility.