If you think of a concert as a stage where the main act is happening, then this could be like the stage inside a cell. The concert aisles between the seats could be the intracellular fluid. And all the people in the audience could then be the organelles because they all are paying attention to what is happening on the stage, just like all the parts of a cell are controlled by the nucleus. Finally, you could imagine the walls of the concert hall as the cell membrane, the phospholipid bilayer that contains all the stuff inside the cell and regulated which come in or are allowed out. This would then be just like the jobs of the cytoplasm, the nucleus, the intracellular fluid, and the organelles.