What does 'adb forward tcp:8080 tcp:8080' command do?

Question

While working on Android development, I have come across the command adb forward tcp:8080 tcp:8080 many times. What does it actually do? and why 8080?

Answer 1

Basically means that the requests on specific port on the host will be forwarded to a specific port on the device. Where the first port is the host and the second one is the device port.

From the docs

forwarding of requests on a specific host port to a different port on an emulator/device instance