When you’re working on a PCB layout, you are editing a file that is specific to your CAD software. It’s not a universal file format, and it uses information that the PCB manufacturer does not need. This is why you have to generate a different sort of file (with an exception we’ll discuss at the end of the article) when you’re ready to convert the virtual layout into a physical circuit board.you can refer how to generate Gerber file from design software.