The mostly common and widely accepted for PCB fabrication is Gerber files. The Gerber format is an open ASCII vector format for 2D binary images. There are 2 major generations of Gerber format:

  • Extended Gerber, or RS-274X. This is the current Gerber format. In 2014, the graphics format was extended with the option to add meta-information to the graphics objects. Files with attributes are called X2 files; those without attributes are X1 files.
  • Standard Gerber, or RS-274-D. This obsolete was revoked.

The standard file extension is .GBR though other extensions are also used.