This is the IP and port specs where the Weaviate is bind to.
The default configuration is 0.0.0.0 (you can see that in the docker compose command section), which means it will receive connection from all origins.
If you are running docker, on that very same commandparametr you also specify at which ports Weaviate will be listening too:
This is because Weaviate is indeed running in port 8080.
Docker can map other ports, that Weavaviate is unaware of.
So if you have your application running also in docker, it will use port 8080 to communicate with Weaviate on an internal network, not the mapped port.