It is about line remove in the WIREFRAME MODE display , without filling faces and all. It is like the fill face limit to visible face only. This will give some speed to vireframe mode when users use a less powefull pc and don`t need to see the extra back lines of the wireframe.
Since i learned retopology, it’s been a dream to have backface culling in wireframe mode.
Wireframe mode is really great when using retopo, but at some point it becomes simply unworkable due to front and back faces being displayed in the same time. Only workaround is to constantly ALT+B to hide part of model, ALT+B to unhide everything, then ALT+B to hide other part of a model, etc… etc…
Hopefully one day we’ll see backface culling available for wireframe mode, would be so usefull.
there is a retopology shading feature in development. The RCS proposal has the “in development” tag and I saw a few tasks on developer.blender.org about it (here’s one I could find back).
in the mean time, there are add-ons. Draw X-ray uses a shading method to put the geometry of the edited object “on top” of other objects using a distance threshold and Backface Hiding (made by yours truly) simply uses the face normals like backface culling does, except not in real-time but with the push of a button. Finally there’s Retopoflow which does a lot of things including a similar shading method to Draw-XRay. They all have their pros and cons and use cases. If you need the hiding feature but don’t need other retopo tools. In terms of pricing, Backface Hiding is completely free, Draw X-Ray is a “pay what you want” on Gumroad and Retopoflow is currently $86.
That’s different. Poke a hole in the front of that mesh and you’ll see what’s in the back. With backface culling you wouldn’t. That’s what the add-ons I mentioned address.