diff --git a/README.md b/README.md
index e9105d9c5a..32564fc1e2 100644
--- a/README.md
+++ b/README.md
@@ -98,6 +98,10 @@ deploying agents:
 
 ## 🏁 Feature Highlight
 
+> **Beginner note:**
+>
+> In ADK, an *agent* is a Python object that defines how your AI system behaves — including its instructions, the tools it can use, and how it responds to users. The example below shows the simplest way to define a single agent.
+
 ### Define a single agent:
 
 ```python