No problem!
LGCIU - Landing Gear Control Interface Unit. The aircraft has 2 of these. These are the "brains" of the landing gear system. They give orders and information to bits of the areoplane that need it about the what the landing gear is doing. ie is it up/down/unlocked etc. Also they sequence the movement of the landing gear itself. Amongst other things!
GPWS - Ground Proximity Warning System. Every commercial aircraft has one and it does exactly what it says on the tin - warns the crew of ground in close proximity. Some give warning of ground ahead of the aircraft (Enhanced GPWS), but most only look down not forwards.
FADEC - Full Authority Digital Engine Control. Each engine has one. Basically an advanced version of what's in most posh cars these days. It basically looks after and controls the engine and all it's parameters.
FCOM - Flight Crew Operating Manual. The Airbus acronym for the aircraft's technical manuals. There are 4 in the series - all cover different things.
The original question related to why the Number 1 (left-side) reverser (the part of the engine that provides reverse thrust for braking after landing) doesn't work when LGCIU 1 doesn't work. The answer is that for the reverse thrust to work, the FADEC (which controls reverse thrust for its individual engine) must receive a signal from LGCIU 1 that the left main landing gear is on the ground. This is to make sure that reverse thrust can never happen in the air - the aircraft would possibly crash if it did. However, when LGCIU 1 doesn't work, the FADEC on engine 1 doesn't get that signal and therefore will not allow reverse thrust on that engine because it doesn't know that the aircraft has landed. All about safety really.
Hope that helps and is not too long-winded!!!
Cheers
