full integration

What does fully intergrated mean.

In what context?

fully integrated glass cockpits (avidyne, garmin).

Everything talks to everything else!

en.wikipedia.org/wiki/Glass_cockpit

Basically all of the instrumentation systems and some aircraft systems are controlled and/or displayed in one place.
Ex: The primary flight instruments, navigation, engine instruments, environmental controls, aircraft controls (flaps, spoilers, gear), transponder, traffic avoidance, weather, yadda all in one or two devices.