Ok guys, let's stop for a second now. Remember PSP? Remember how we talked about OFW (Official Firmware) and CFW (Custom Firmware)? Wellp, it does not make any sense for 3DS. Remember cakesFW and the infamous firmware.bin everyone forgot about since the first release of luma? Well, that's the 3DS's actual firmware and it's about a megabyte or so long (up to 8 MB? if i'm not mistaken). The rest of the system, the rest of the space up to 900, 1200, 1600 MB are mostly system titles (check 3dbrew). How do we may call them? System titles, operating system, home menu? Idk. But they. are. not. firmware. In fact, you can have the 3ds firmware in a version, have the NVER and the CVER titles in another version and have the rest of system titles in an intermediate version (between firm and NVER-CVER) and system will boot (Probably not fully working but will boot).
So please refer to the 3DS software version as software version, the firmware version as firmware version and anything in between just specify.