Hi Diego,A level is defined by the work planes. When a level is created it is active. You can tell it is active because the text is bold. Each element that is created on a level that is active will be attached to it. If you change the level height the item will move with it. If you want to move the item alone you must detach it from the Workplanes tab. Right click on the level and from the contextual menu select detach, you will be prompted to select which elements you want removed from the level work plane along with their Geometry points.To view all your levels select the structures button then hit the eye icon in the upper right of the dialog box.If you erase a level you will be prompted with a warning “Do you want to delete all the objects on this level? If you choose Yes, all the elements created and attached on the level will be deleted.See the links below for additional information.Graitec FAQs – How are elements attached in Advance Steelhttp://www.graitec.com/en/FAQ_view.asp?FAQID=847&Language=EN&Name=How+are+elements+attached+in+Advance+Steel?Model views & Project explorer AS 2011 (See time line 6:30)https://www.youtube.com/watch?v=q3aS7C3T4pQModel views & Project explorer (See time line 6:30)https://www.youtube.com/watch?v=HMuFEdoBhpgHope this helps,Best Regards