DWG is a binary file format used for storing two and three dimensional design data and metadata. It is the native format for several CAD packages including AutoCAD, IntelliCAD and Caddie. In addition, DWG is supported non-natively by many other CAD applications. The .bak (drawing backup), .dws (drawing standards), .dwt (drawing template) and .sv$ (temporary automatic save) files are also DWG files.
DWG was the native file format for the Interact CAD package, developed by Mike Riddle in the late 1970s, and
subsequently licensed by Autodesk in 1982 as the basis for AutoCAD.From 1982 to 2009, Autodesk created versions of AutoCAD which wrote no fewer than 18 major variants of the DWG file format, none of which are publicly documented.
The DWG format is probably the most widely used format for CAD drawings. Autodesk estimates that in 1998 there were in excess of two billion DWG files in existence.

DXF, which stands for Drawing Exchange Format, is a file format used by AutoDesk computer-aided design (CAD) files. They can be opened in programs such as AutoCAD, but are compatible with other vector-based programs, making it useful for collaborating and sharing files. DXF is also used to convert a Portable Document Format (PDF) to a CAD file without AutoCAD. Although there are no free online converters, there are a few programs that allow you to do it using a free trial.
Data format developed by Autodesk and used for CAD (computer-aided design) vector image files, such as AutoCAD documents; similar to the .DWG format, but is more compatible with other programs since it is ASCII (text) based.
The DXF format was developed as a universal format so that AutoCAD documents could be opened more easily with other programs. For example, the Valve Hammer Editor can export 3D models as DXF files, which can be opened and edited with other 3D modeling applications.

Then let us talk about the PDF format, invented by Adobe Systems and perfected over 17 years, Portable Document Format (PDF) is the global standard for capturing and reviewing rich information from almost any application on any computer system and sharing it with virtually anyone, anywhere. With the launch of Adobe® Acrobat®X
software, PDF is more secure and dynamic than ever. individuals, businesses, and government agencies around the world trust and rely on PDF files to communicate their ideas and vision. So it is necessary for us to learn something about Portable Document Format.
A Portable Document Format (pdf) file is a self-contained cross-platform document. To put it simply, it is a file that will look the same on the screen and in print, regardless of what kind of computer or printer someone is using and despite what software package was originally used to create it. What’s more, it allows you to read electronic documents, either on or off line. This format provides a page-by-page view of documents, exactly as they appear in their printed form, as well as allowing keyword search.

Although they contain the complete formatting of the original document, including fonts and images, PDF files are highly compressed, allowing complex information to be downloaded efficiently.

Do you have any concept of the three file formats after reading the above text? I think you must have, all the three formats have their own features and powerful functions, but there are also some shortages of them, for example, if you have files of pdf formats and want to edit the files, but the pdf format do not support the action, the DWG and DXF format allows you to do that , so one way is to convert PDF to DWG or DXF and you can use the two software named PDF to DWG Converter and PDF to DXF Converterto help you do all things, there are even step by step guide about how to Convert PDF to DWG.