You can group elements together for easier designing.
To group elements, select them in the layers panel or on the artboard by holding shift. Once your layers are selected, right-click and select Group Layers. All of the selected layers will group into a folder. When you want to select all of the layers in the group, click on the folder in the layers panel.
To ungroup layers, click on the grouped layer, then right-click and select Ungroup Layers.