diff --git a/docs/component/component.md b/docs/component/component.md
index b2d08b3..f56d953 100644
--- a/docs/component/component.md
+++ b/docs/component/component.md
@@ -1,4 +1,4 @@
-*| [JavaECS](../../README.md) | [docs](../overview.md) | component*
+*| [JavaECS](../../README.md) | [docs](../overview.md) | [component](./dir.md) | component[]().md*
 # Component
 
 ### Contents
diff --git a/docs/component/dir.md b/docs/component/dir.md
new file mode 100644
index 0000000..aabceaa
--- /dev/null
+++ b/docs/component/dir.md
@@ -0,0 +1,4 @@
+*| [JavaECS](../README.md) | [docs](../overview.md) | component*
+# Overview
+### In this folder
+[component.md](./component.md)
\ No newline at end of file
diff --git a/docs/entity/dir.md b/docs/entity/dir.md
new file mode 100644
index 0000000..63296e8
--- /dev/null
+++ b/docs/entity/dir.md
@@ -0,0 +1,4 @@
+*| [JavaECS](../README.md) | [docs](../overview.md) | entity*
+# Overview
+### In this folder
+[entity.md](./entity.md)
\ No newline at end of file
diff --git a/docs/entity/entity.md b/docs/entity/entity.md
index e2cb55a..595849b 100644
--- a/docs/entity/entity.md
+++ b/docs/entity/entity.md
@@ -1,4 +1,4 @@
-*| [JavaECS](../../README.md) | [docs](../overview.md) | entity*
+*| [JavaECS](../../README.md) | [docs](../overview.md) | [entity](./dir.md) | entity[]().md*
 # Entity
 
 ### Contents
diff --git a/docs/implementation.md b/docs/implementation.md
new file mode 100644
index 0000000..ceff74e
--- /dev/null
+++ b/docs/implementation.md
@@ -0,0 +1,61 @@
+*| [JavaECS](../README.md) | [docs](./overview.md) | implementation[]().md*
+# Implementation
+### Contents
+[Steps](#Steps)
+
+[Example](#example)
+
+## Steps
+1. In the application's setup function, create an instance of `ECS`, with a specified maximum number of entity entries.
+2. Define the component classes, (or associate the primitive types) and register the components.
+3. Define the systems that interact with the components and register them
+4. Run the game.
+
+## Example
+``` java
+public static void main(){
+    ECS gameEngine = new ECS(100);
+    // Register the components, with a parameterised type
+    gameEngine.registerComponent<coord>(coord.class.getName());
+    gameEngine.registerComponent<ridgidBody>(ridgidbody.class.getName());
+    // Register the system to run on the component
+    gameEngine.registerSystem("ApplyGravitySystem", () -> {
+        List<Integer> relevantEntities = gameEngine.getEntitiesWithComponent(ridgidBody.class.getName());
+        for (Integer entity : relevantEntities) {
+            coord c = (coord)gameEngine.getComponent(entity, coord.class.getName());
+            ridgidBody r = (ridgidBody)gameEngine.getComponent(entity, ridgidBody.class.getName());
+            c.y -= r.gravity;
+        }
+    });
+    // Create an acutal game object
+    int someEntity = gameEngine.createEntity();
+    // Assign components to the new game object
+    gameEngine.addComponent(someEntity, coord.class.getName(), new coord());
+    gameEngine.addComponent(someEntity, ridgidBody.class.getName(), new ridgidBody());
+    // Finally, enter into the game loop
+    gameEngine.loop();
+
+}
+
+class coord{
+    double x = 0.0;
+    double y = 0.0;
+}
+
+class ridgidBody{
+    double gravity = -9.81; // has a default value, unless overridden in the constructor
+    ridgidBody(){}
+    ridgidBody(double gravity){
+        this.gravity = gravity;
+    }
+}
+```
+
+
+
+### See also:
+[entity](./entity/entity.md)
+
+[component](./component/component.md)
+
+[system](./system/system.md)
diff --git a/docs/overview.md b/docs/overview.md
index f108169..783ca38 100644
--- a/docs/overview.md
+++ b/docs/overview.md
@@ -1,7 +1,7 @@
 *| [JavaECS](../README.md) | docs*
-# Entity
-### Contents
-[About](#About)
+# Overview
+### In this folder
+[Implementation](./implementation.md) *how to use JavaECS*
 
 [Usage](#Usage)
 
@@ -14,3 +14,4 @@
 
 [system](./system/system.md)
 
+
diff --git a/docs/system/dir.md b/docs/system/dir.md
new file mode 100644
index 0000000..76eac34
--- /dev/null
+++ b/docs/system/dir.md
@@ -0,0 +1,4 @@
+*| [JavaECS](../README.md) | [docs](../overview.md) | system*
+# Overview
+### In this folder
+[system.md](./system.md)
\ No newline at end of file
diff --git a/docs/system/system.md b/docs/system/system.md
index dfab437..377729d 100644
--- a/docs/system/system.md
+++ b/docs/system/system.md
@@ -1,18 +1,28 @@
-*| [JavaECS](../../README.md) | [docs](../overview.md) | system*
+*| [JavaECS](../../README.md) | [docs](../overview.md) | [system](./dir.md) | system[]().md*
 # System
 
-### Contents
+### In this section
 [About](#About)
 
 [Implementation](#Implementation)
 
 [Examples](#Examples)
 
+[Notes](#Notes)
+
+
 ## About
 The system runs operations that must be performed on its assoiciated components.
 
 Typically, this is expected to be run every frame, though this is not a strict requirement.
 
+A system must implement the Runnable interface (this is a limited case of inheritence in this library)
+
+This allows a simpler implementation of any system, and also allows concurrency to be implemented with relative ease.
+
+
+
+
 Examples of the `system` include the `health_system`; which reads the value of the entitie's `health` component and ensures h > 0.
 ``` java
 void health_system(){
@@ -44,4 +54,9 @@ class SystemManager{
 
 ## Examples
 
+## Notes
+* Each system is represented by a name-index pair, and the action that gets executed every time the system is performed.    
+    * This is implicitly sequential, but a custom system that performs concurrent actions can be implemented.
+    * Care must be taken to ensure all threads are synchronised before the concurrent system finishes its execution
+