ICA protocol

ICA is another display protocol that is used by Citrix in its products, XenDesktop and XenApp. It is similar in design to other protocols in that it is used to deliver screen content and keyboard strokes to a client device over a TCP IP network connection.

You connect using an ICA client, such as Citrix Receiver, installed on your endpoint device. This loads an ICA file containing the details of the remote system you are connecting to and any properties to apply to that session.

What about High Definition Experience (HDX)? HDX is not a protocol or a technology, but rather a marketing brand for HDX. HDX encompasses a number of Citrix technologies that describe the entire user experience rather than concentrating on just the protocol element. You will also see some sub-brands fall under HDX, such as HDX MediaStream, HDX RealTime, and HDX 3D.