yes most likely more complicated than that.. Supports are structures that get 3d printed underneath areas of the print that are not supported.. The plastic can not print in midair gravity prevents that. The slicing software knows where these unsupported areas are and prints pillars of some sort (different in each software) to support the area that is hanging with nothing under it. Once the print is complete these supports get removed with small tools. There are different settings that control how the supports work so it is not just check the box.. 3D printing is not plug and play.. some science some art.. supports are kind of the art part.. knowing when and how much takes trial and error to learn. If you slicer has a preview pane, move the slider so you can watch the print grow then click the add supports and do it again, you should see the supports show up in the preview.. not knowing anything about your slicer I can say for sure but that is how it works in S3D.