docs/tut/crash-course/1-introduction.md

@@ -24,3 +24,24 @@ Some of the main focuses behind Vide's design choices:
 - Independence from instance lifetimes.
 - A powerful reactive system that can surgically update properties as a result
   of state changes.
+
+## Structure Of A Vide App
+
+The entry point for all Vide apps is the `root()` function. This function
+sets up Vide's reactivity system and allows proper disposal of your app. It
+takes and calls a function that should create your entire app, then returns the
+result.
+
+In Vide, your app should be composed of functions, each function creates a
+specific part of your app, and can be reused if needed. These functions are
+called *components*.
+
+```lua
+local function App()
+    return create "ScreenGui" {
+        create "TextLabel" { Text = "hi" }
+    }
+end
+
+root(App).Parent = game.StarterGui
+```