What does this traffic sign indicate?

This traffic sign indicates a speed limit zone where the maximum permitted speed is 30 km/h. In Germany, such signs mark an area where you must not exceed 30 km/h for the entire zone, not just at a single point. This helps improve safety in residential or sensitive areas by slowing down traffic consistently throughout the zone. It is different from a minimum speed or a recommended speed, which would be indicated by different signs and shapes. Always adhere to this speed limit to ensure safety and avoid fines.