The .drawio file format is used by draw.io (now diagrams.net), a free, open-source diagramming application. It stores diagrams, flowcharts, UML diagrams, mind maps, and other types of visual representations. The file itself is typically an XML-based format that contains the diagram's structure, elements (shapes, connectors, text), attributes (colors, sizes, fonts), and layout information. Because it's XML-based, the content is often human-readable, though not easily editable directly. draw.io files are designed to be platform-independent, allowing users to create and edit diagrams on various operating systems and web browsers. The format supports a wide range of diagramming conventions and allows for collaboration through features like real-time co-editing (depending on the platform used to access draw.io). The diagrams can be exported to various other formats like PNG, JPG, SVG, PDF, and more, making it versatile for sharing and integration with other applications and documents. The drawio format is the native format for saving diagrams within the draw.io environment, preserving all diagram elements and their properties for future editing.