Cytobank treats Gates and Populations as separate (but related) entities. When you draw a gate, that gate defines a population of cells. But it is also possible to define a population of cells based, for example, on the intersection of two or more gates (without that new population being defined by its own single, unique gate). This can be accomplished from within the Populations Manager in the Gating applet (click the "Manage" button in the Gating applet).