diff --git a/azure/terraform/README.md b/azure/terraform/README.md
index 4387d3c..96b8bbe 100644
--- a/azure/terraform/README.md
+++ b/azure/terraform/README.md
@@ -1,37 +1,65 @@
+# What
+
+Terraform allows to transparently declare our infrastructure as code.
+
+
+# The road so far
+
+Only the vault is defined within the `vault.tf` file.
+
+Vault is composed of:
+- one api allowing to request object cooking or retrieve cooked objects
+  (objstorage, db)
+- this also uses a storage to read the swh archive (azure:
+  storage0.euwest.azure)
+
+The vault.tf defines here:
+- existing:
+  - subnet (reuse)
+  - security-group (reuse)
+- new resource:
+  - euwest-vault: to group together the allocated resource for the vault
+  - vangogh-interface: to define an ip for the new server vangogh
+  - vault-storage: storage account for the BlobStorage necessary for the
+    objstorage api of the vault (including a container "contents" to actually
+    store the blobs)
+  - vault-server: the 'vangogh.euwest.azure' vm to actually serve the vault api
+
 # Install terraform
 
 https://learn.hashicorp.com/terraform/getting-started/install.html#installing-terraform
 
 # Login
 
 Through azure cli (for now)
 
 ```
 az login
 ```
 
 # Init
 
 ```
 terraform init
 ```
 
 # Plan changes
 
 This will compute all *.tf files present in the folder and compute a
 differential plan:
 
 ```
 terraform plan
 ```
 
 Note: It might be a good idea to change the `variables.tf` file to adapt for
 example the admin user and its associated public key
 
 # Apply changes
 
-Same as previous command except that it applies the diff to the infra:
+Same as previous command except that it applies the diff to the infra
+(interactive):
 
 ```
 terraform apply
 ```