Emmerich am Rhein
Stockpile (temporary pile created during season, any number of cubes)
Storeroom (move cubes from stockpile to storeroom, limited by your colony level)
I would assume reserve = stockpile?
During your turn you indeed can have more cubes than the size of your storage room (4 or 6).
The order of play in a round is also displayed at a player board.
4 is harvesting the cubes from the main board so at this moment you possibly have more cubes than the size of your storeroom.
5 is the atelier where you can invest cubes in new technologies.
6 is where you have to discard the cubes you cannot store.