From 54377f8ac26f0a59790520a59279dc8b5ec7f977 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Costin=20Caraba=C8=99?= <costin.carabas@gmail.com>
Date: Thu, 26 Oct 2023 14:43:21 +0300
Subject: [PATCH] Introduction: Devnet & Testnet

---
 .../lab/content/explorer/devnet_testnet.md    | 21 +++++++++++++++++++
 .../lab/content/explorer/observers.md         | 16 ++++++++++++++
 config.yaml                                   |  1 +
 3 files changed, 38 insertions(+)
 create mode 100644 chapters/introduction/lab/content/explorer/devnet_testnet.md

diff --git a/chapters/introduction/lab/content/explorer/devnet_testnet.md b/chapters/introduction/lab/content/explorer/devnet_testnet.md
new file mode 100644
index 00000000..24a70561
--- /dev/null
+++ b/chapters/introduction/lab/content/explorer/devnet_testnet.md
@@ -0,0 +1,21 @@
+# Devnet & Testnet Blockchain
+
+While developing applications, there is a need for a development/testing blockchain.
+
+Inspect:
+* [MultiversX Testnet Explorer](https://testnet-explorer.multiversx.com/)
+* [MultiversX Devnnet Explorer](https://devnet-explorer.multiversx.com/)
+* [Goerli Ethereum Testnet Explorer](https://goerli.etherscan.io/)
+* [Sepolia Ethereum Testnet Explorer](https://sepolia.etherscan.io/)
+
+What differences can you observe?
+
+These blockchains offer the `Faucet` option where you can mint blockchain tokens (eGLD, ETH, etc.).
+This way the development is easier for the community.
+
+---
+**NOTE**
+
+All the tokens are "fake" tokens. They are only used to mock the real tokens on the Mainnet.
+
+---
diff --git a/chapters/introduction/lab/content/explorer/observers.md b/chapters/introduction/lab/content/explorer/observers.md
index e69de29b..8314aa08 100644
--- a/chapters/introduction/lab/content/explorer/observers.md
+++ b/chapters/introduction/lab/content/explorer/observers.md
@@ -0,0 +1,16 @@
+# Observers
+
+Observers are a type of nodes that `don't participate in the consensus` but keep a peer-to-peer communication with the rest of the blockchain.
+They are usually used to see the communication between nodes (ex: debugging). 
+
+Let's filter the nodes to see only the observers. There is an [Observers](https://explorer.multiversx.com/nodes?type=observer) tab below the `Nodes` section.
+
+![Observers](../../media/observers.png)
+
+We can observer the same fields as the nodes, but there is no `Rating`. Why is that?
+
+Note that each Observer is only on a Shard.
+
+What should we do if we want to listen to the communication on every shard?
+
+Observer that there are other types of nodes
\ No newline at end of file
diff --git a/config.yaml b/config.yaml
index f3afe118..c7048fc0 100644
--- a/config.yaml
+++ b/config.yaml
@@ -73,6 +73,7 @@ docusaurus:
                 - Transactions/: transactions.md
                 - Blockchain Validators/: validators.md
                 - Blockchain Observers/: observers.md
+                - Devnet Blockchains/: devnet_testnet.md
           - Observer:
               path: chapters/introduction/lab/content/observer
               extra: