What does this traffic sign indicate?

The traffic sign in the image indicates a cul-de-sac (dead-end street). This sign serves to inform drivers that the road ahead does not continue and terminates in a circular area or a closed section. Understanding this sign is crucial for drivers to avoid unnecessary or confusing navigation, especially in unfamiliar areas. It is part of German traffic regulations which help maintain order and safety on the roads by ensuring that drivers are well-informed of the road conditions ahead.