Swiping from the screen edge towards the center of the screen allow you to activate effects. Here you can configure which effect will get activated on each edge of the screen.
Click with any mouse button onto a square and select an effect in the context menu. Edges with a blue square have already an attached effect, a grey-colored square indicates that no effect is selected for this edge.
The number of accessible items in the context menu depends on the settings in the module Desktop Effects in the Workspace category. Select your favorite effects from the Window Management group. This activates the corresponding items in the context menu.