I'm new to 3D printing and OctoPrint. I was reading through the generated GCode files for better understanding and found certain lines at the top of the file starting with ' ; ' Are those similar to comments in other programming languages are do they convey any message to the 3D printer.
Anything after a ; (or after a #) is considered a comment and ignored by most printers. OctoPrint usually strips these parts from the gcode before sending it to the printer.
Pay special attention to the commands which change the mode (absolute versus relative) of the motors and the extruder.
I already upgraded my firmware to Marlin 1.1.x. Is there a basic guide for Marlin firmware?