DXF or DWG: the real difference
It is not a question of quality or precision. It is a question of how open the format is.
The answer in three lines
Both formats come from Autodesk and carry the same geometry, layers and dimensions. DXF has a published specification, so every CAD program reads it officially. DWG is AutoCAD's native format, binary and unpublished: other vendors read it through reverse engineering, which works almost always and breaks occasionally. Send DXF when you do not know the software at the other end, DWG when the whole chain is Autodesk.
What sets them apart
DXF
An exchange format whose specification is published by Autodesk. Comes in a text variant, readable in an editor, and a more compact binary variant.
DWG
AutoCAD's native format, binary, with an unpublished specification. More compact than text DXF and the only one carrying certain proprietary objects.
When to use which
DXF
When you send a file to someone whose software you do not know, when a contract requires an open format, or when the recipient works in open-source CAD.
DWG
When everyone works in AutoCAD, when you must preserve dynamic blocks or Autodesk objects, or when the file is very large.
Both formats exist in several yearly versions. A recent DXF may not open in an older CAD: on export, dropping one or two versions solves almost every rejection.
Frequently asked questions
Do you lose data by going to DXF?
Not the geometry, not the layers, not the dimensions. AutoCAD-specific objects, dynamic blocks and parametric objects, do get flattened into plain geometry. For a takeoff or a construction drawing, that changes nothing.
Does AutoCAD open DXF without conversion?
Yes, natively, since Autodesk created the format. Sending a DXF to an AutoCAD user requires no extra step on their side.
Other common confusions
What if the plan did the work?
FloorScan reads a PDF, produces areas and lengths, and exports in whatever format your counterpart expects.