As far as im aware most of Europe’s dispatchers generally work for the handling agents contracted to the Airline’s and do the following:
Coordinate ground operations… fuel, catering ect
Arrange stands/air bridges
Produce the load sheet
Provide current weather
Coordinate pushback (Headset man)
Liaise with the Airline
As for Operations Officer’s/ Operations Controllers they work for the Airline and generally do the following:
Flight planning, over flight clearance, runway slots
Provide crews with computerised flight plans/en-route weather
Ensuring crew’s are legal to fly (FTL, medicals and currency ect)
Coordinate the Airline’s flying program (flight watch)
Liaison with the handling agents
This is a very brief account of what’s done but I hope it gives you a slight idea how it works
HS