can anyone explane to me what is steinberg eucon adapter. sorry if i sound like a dummy, but just wanted to no why and what it does for cubase
Looks like it is software that is required to have installed with certain Cubase versions if you want your Avid Artist and Pro Series Controller to work properly.
“The Steinberg EuCon Adapter for Cubase 6.5.0 and Nuendo 5.5.4 available here is required for the use of the AVID Artist and Pro Series Controllers.”
Regards 
They also do an app for iPad which can control cubase and it requires eucon
Since Cubase version 7 ( I believe), The EuCon Adapter is embedded within the Cubase installers, so no need to download the EuCon Adapter separately, unless you are still using an early version of Cubase, and then you would also need to be running earlier versions of EuControl. ( AVID’ s part of the solution, which depending on your version of EuControl… also requires you to have the right firmware installed in the controllers themselves).
Welcome to the party pal! 