While preparing for XenApp 6.5 I came across this good explanation by David Gaunt about session pre-launch within XenApp 6.5. David explains the CCU model very good and how it is used with session pre-launch.
“A bit of background
Before we go forward, lets take a few steps back over some familiar technology.
Remember in the old days when you would launch a Presentation Server app with a click of an icon and…wait…wait…logon script fires up…profile loads…wait a moment more…ta-dahh, you’re app is ready? Well we, and a few other clever partners, managed to reduce application launch time by doing clever things with the user profile or just trimming the fat that was the traditional roaming profile. But it was never going to be ‘like-local,’ which is really the end-goal of any virtual desktop solution.
In XenApp 6.5 we’ve cracked this launch delay by using a combination of the latest Windows Receiver and a new feature called Session Pre-Launch. Using this feature will mean than any application will start up immediately, without any delay.”
You can read the complete blog here.