diff --git a/1-intro-to-smart-infra.md b/1-intro-to-smart-infra.md
index 3b37a0c..cd7b552 100644
--- a/1-intro-to-smart-infra.md
+++ b/1-intro-to-smart-infra.md
@@ -25,7 +25,7 @@
     - Data collected contains observations (values), and attributes / features
       (keys), can be:
         - Continuous or Discrete
-        - Numeric or nominal
+        - Numeric or nominal (labels like "London" or "Beijing")
 1. Modeling: Visualizing the data to answer questions
     - Using ML: split dataset to train, validate and test them
         - Train: to fit the model