diff --git a/poc-datacollector/modules/ROOT/nav.adoc b/poc-datacollector/modules/ROOT/nav.adoc
index e0b2398..8183566 100644
--- a/poc-datacollector/modules/ROOT/nav.adoc
+++ b/poc-datacollector/modules/ROOT/nav.adoc
@@ -1,6 +1,6 @@
 * xref:index.adoc[datacollector]
 * xref:index-structure.adoc[project structure]
-** xref:index-vuejs.adoc[Vue.js]
+** xref:index-vuejs.adoc[Vue.JS]
 ** xref:index-nodejs.adoc[Node JS]
 ** xref:index-mongo.adoc[Mongo]
 ** xref:index-redis.adoc[Redis]
diff --git a/poc-datacollector/modules/ROOT/pages/index-nodejs.adoc b/poc-datacollector/modules/ROOT/pages/index-nodejs.adoc
index 08b38cf..e27a024 100644
--- a/poc-datacollector/modules/ROOT/pages/index-nodejs.adoc
+++ b/poc-datacollector/modules/ROOT/pages/index-nodejs.adoc
@@ -38,6 +38,26 @@ Child processes can be spawned by using our *child_process.fork() API,* and are
 TIP: Built upon that same interface is the cluster module, which *allows you to share sockets between processes* to enable load balancing over your cores.
 
 
+== socket.io
+
+*Socket.IO* is a library that enables *real-time*, *bidirectional* and *event-based* communication between the browser and the server.
+
+It consists of:
+
+- a Node.js server: Source | API
+- a Javascript client library for the browser (which can be also run from Node.js): Source | API
+
+image::bidirectional-communication.png[]
+
+https://socket.io/[See more info here: Socket.io^]
+
+
+== express
+
+Express is a minimal and flexible Node.js web application framework that provides a robust set of features for web and mobile applications.
+
+*Fast, unopinionated, minimalist web framework for Node.js*
+
 == Video = intro