Simplify3D is software called a "slicer" that you use to make the code that the printer uses to make the print. It translates a 3D model into step-by-step code to tell the printer what to do. There are many slicers available, most are free such as Cura and IdeaMaker. Simplify3D is not free, but it does a great job and is fairly well organized. I (Satre) am biased, however, since it's the only slicer I've really used extensively. Cura is also extremely good and is a little more advanced than Simplify3D in some areas.
Simplify3D is on the Windows machine to the right of all the printers. It already has printing profiles for PLA and for PETG built in. If you are unfamiliar with using slicer software, please utilize the tutorials below
Cura is a very popular slicer made by Ultimaker, and is open source. As of this writing, there are no profiles set up for our printers, but with help, we will get some put in, hopefully soon.
IdeaMaker is made by Raise3D and is free. Ditto on no profiles in yet.