A droid programming chip is a chip containing a ship command that was programmed by a pilot. This allows pilots to use commands from different faction pilots.
When a droid programming chip is used on a flight computer or astromech droid that chip is destroyed and cannot be reclaimed.
An Unprogrammed Droid Command Module can be made by an Engineer, a pilot is then able to use the chip to program one of their own commands into it. Once programmed with a specific command that chip cannot be wiped and returned to an Unprogrammed Droid Command Module, it must be used or destroyed.