***Gerber**: Typically define copper layers in a circuit board.
***Excellon**: (drill file): Contain drill specifications, size and coordinates.
***G-Code**: CNC machine instructions for cutting and/or drilling.
These source files can be loaded by selecting File→Open Gerber…, File→Open Excellon… or File→Open G-Code… respectively. The objects created from source files are automatically added to the current project when loaded.
Data in FlatCAM is in the form of 4 different kinds of objects: Gerber, Excellon, Geometry and CNC Job. Gerber, Excellon and CNC Jos objects are directly created by reading files in Gerber, Excellon and G-Code formats. Geometry objects are an intermediate step available to manipulate data. The diagram bellow illustrates the relationship between files and objects. The arrows connecting objects represent a sub-set of the tasks that can be performed in FlatCAM.
..image:: objects_flow.png
:align:center
Creating, Saving and Loading Projects
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A project is everything that you have loaded, created and set inside the program. A new project is created every time you load the program or run File→New.
By running File→Save Project, File→Save Project As… or File→Save a Project Copy… you are saving everything currently in the environment including project options. File→Open Project… lets you load a saved project.
Plots for open objects (Gerber, drills, g-code, etc…) are automatically shown on screen. A plot for a given can be updated by clicking “Update Plot” in the “Selected” tab, in case any parameters that would have changed the plot have been modified.