This page should help you understand the basic function of configs.
This is where you setup your addon name and some small stuff like requiredaddons etc.
These are the ammo projectiles that are fired from weapon, these are doing the damage on anything they hit. Ammo can be bullets, rockets, bombs, etc.
Magazines are the items that hold the ammo, ie cfgAmmo entries. For example your usual M16 magazine says it hold 30x the 5.56mm ammo.
Weapons are the actual weapons that fire the ammo, which is stored in the magazines. Weapons can be held by Man class units, vehicles or static weapons.
Vehicles are pretty much everything that can be “played”. The most common cfgVehicle item is a Man class soldier. Then there is vehicles, static weapons and objects which mostly are placed into mission editor, like bunker or a tree etc.
These are the terrains, everything about how terrain is setup in the pbo, its name and grid coordinates, name labels etc come from this config.
Recoils are for the man class weapons, they are linked to the cfgAmmo. When you fire a ammo, the cfgWeapons config is checked of the weapons recoils, which are setup here.