The numbers before the - mark is the firmware version.  This may have letters added at the end (like 2.0a) to indicate a printer version specific fix that doesn't materially change the base firmware version  (2.0a is equivalent to 2.0 for all other printers, etc).
The first number after the - mark is the head
-- 1 is original head
-- 2 is all metal head
The second number after the - mark is the main board
-- 1 is the original full sized board
-- 2 is the new mini sized board
The third character, if present, indicates a feature value
-- h or H indicates a heated bed

If a firmware does not have two numbers after the dash (and is earlier than 2.0) then the printer is a type 11.  Possible early values are -1, -2h, and -0.


1.1 is old version Marlin
2.0 is 1.1.0-RC3

Copy order is...
-- build 22
-- copy 22 to 21, modify for fans
-- copy 22 to 12, change for heads only
-- copy 21 to 11, change for heads only


----

Note that differences are...
-- Board type definition (Rambo)
-- PID values (Head)
-- Full rambo combines fans on one pin out, mini uses 2 sep pin outs.  Conf_adv near line 110 EXTRUDER_1_AUTO_FAN_PIN (Rambo)
-- Fan power changes, Conf_adv EXTRUDER_AUTO_FAN_SPEED is 255 for new head and 200 for old head (Head)

Also note that...
-- Line 72 Conf Adv EXTRUDER_RUNOUT_PREVENT disabled due to bug, all versions on RC3 (All)