diff --git a/Modules.mediawiki b/Modules.mediawiki
index 92f660a..08a37f4 100644
--- a/Modules.mediawiki
+++ b/Modules.mediawiki
@@ -1,5 +1,22 @@
 Assets for the game — images, sounds, even the game codes are packed into '''Modules'''.
 
+Modules in Terrarum is divided into two categories: the Internal Module and the User Module.
+
+== The Internal Modules ==
+Internal Modules comprises the "base game" of your own game that are not expected to be modified by the end user. When your game is packaged (e.g. via AppImage), the Internal Modules become read-only.
+
+Internal Modules are stored under <code><game exec dir>/assets/mods/</code>.
+
+== The User Modules ==
+User Modules are "mods" for your game, and can be modified by the end user.
+
+User Modules are stored under <code><appdata>/Modules/</code>.
+
+== Configurations Generated by Modules ==
+Modules' default config must be found under <code><module root>/default.json</code>. Any config changed by the user will be stored onto the <code><appdata>/config.json</code>, along with the engine's base config.
+
+The user config will have a key with <code><module name>:</code> prepended: for example, if the module <code>basegame</code> contains config key <code>gameplay_max_crafting</code>, the user-modified config will be named as <code>basegame:gameplay_max_crafting</code> on the <code><appdata>/config.json</code>.
+
 == Loading Modules ==
 * [[Modules:Load Order|Module Organisation]], aka Load Order
 * [[Modules:How to Get Started|The Entry Point]]
@@ -18,4 +35,4 @@ Assets for the game — images, sounds, even the game codes are packed into '''M
 
 == Other Documentations ==
 * [[Developer:RAW|Creature RAW]]
-* [[Developer:Faction|Faction]]
\ No newline at end of file
+* [[Developer:Faction|Faction]]