AutoCAD - Wikipedia
https://en.wikipedia.org/wiki/AutoCADAutoCAD has included support for .dwf, a format developed and promoted by Autodesk, for publishing CAD data. File formats Filename extensions. AutoCAD's native file formats are denoted either by a .dwg, .dwt, .dws, or .dxf filename extension. The primary file format for 2D and 3D drawing files created with AutoCAD is .dwg.
Drawing file format compatibility in AutoCAD - Autodesk
knowledge.autodesk.com › support › autocadDrawing (. dwg) files are the native data files that are created when using AutoCAD-based products. Each AutoCAD-based product uses the DWG format which was current at the time of its release (see table below) when saving to a file. This is important to know when sharing drawing files. DWG files can be opened using any AutoCAD or AutoCAD product of the same version/year number or newer.
List of file formats - Wikipedia
https://en.wikipedia.org/wiki/List_of_file_formatsThis is a list of file formats used by computers, organized by type. Filename extension it is usually noted in parentheses if they differ from the file format name or abbreviation. Many operating systems do not limit filenames to one extension shorter than 4 characters, as was common with some operating systems that supported the File Allocation Table (FAT) file system.