For our purposes here, a "project" is all the "stuff" that is associated with the making of a particular PCB. The main files are as follows, but there will be others, too… backups, caches, etc.
- Schematic (.sch file, etc)
- Netlist (.net file)
- schematic symbol to Footprint assignments (.net files, and, before vers 4.0.4 or earlier, .cmp files)
- PCB artwork (.brd file (legacy, at 4.0.4))
- The libraries
…. and, of course the file with the ".pro" extension, which is the "one ring to rule them all."
(This entry may need improvement. If you particularly want THIS expanded, write and cite "Page co1proj")