No doubt another college project looking for answers here.....try the Rolls Royce book!!
An OGV is an outlet guide vane.....usually on the outlet of the Fan Flow.
They all do as they say on the tin.....VBV variable Bleed Valve varies opening or closing, a Bleed Valve is open or closed, both maintain the surge margin of the compressor.
Guide Vanes.....Inlet guide vanes or Variable Inlet Guide Vanes, VIGVs? You don't say which.
Never heard of an ordinary Guide Vane.
May be you mean Variable Stator Vanes? VSVs?
All manage the airflow in to a compressor to ensure optimum airflow with RPM and Temperature.