What do these traffic signs indicate?

These signs together indicate a no parking or stopping zone, extending both on the roadway and the hard shoulder (emergency lane). The main round sign with the blue background and red cross means no stopping at any time. The additional white sign below clarifies that this restriction applies not only on the regular lanes but also on the hard shoulder.

In German traffic rules, stopping includes any halting or parking, so you must not stop your vehicle, even briefly, along the entire area covered by these signs on both the road and the shoulder. This ensures that traffic flow and emergency lane access remain clear.