What was the purpose, if no data could be sent back?

So both people send data from themselves to this third party.

And only after all that can you begin to actually send data.

That is, either end can send data to the other.

Very often, this data is then sent over the internet to a third party, which can use it for something.

The data is then sent to a computer for processing.

It is possible to send data over the control channel.

The data will then be sent via the Internet to the doctor.

So those are the two ways that data is sent to a server.

Everything connected to the internet needs an address so data is sent to the right place.