Firmware = the lower partitions you don't often pay attention to - the bootloader, the radio stuff, recovery (that we replace with TWRP) and so forth.
A rom consists of a boot image and the operating system contents that go into the /system partition.
Your apps, updates and private data go into the /data partition.
fastboot getvar all
Tells what's needed for full support.
A rom consists of a boot image and the operating system contents that go into the /system partition.
Your apps, updates and private data go into the /data partition.
fastboot getvar all
Tells what's needed for full support.