If I'm understanding it correctly, you could use it to store values and variables for use in the next session instead of having them be reset. So, I'm making a PMC mission where you can have access to a global bank account which would revolve around a variable such as
bankAccount. Using a CBA delayed per-frame handler you could do
["money", bankAccount] call ALiVE_fnc_setData, and then pull
bankAccount = ["money"] call ALiVE_fnc_getData when I need to have that information back after starting up the mission a 2nd time. Just a guess at this point but it seems that would be the way it works.