diff --git a/cloud.md b/cloud.md
new file mode 100644
index 0000000..af66c8f
--- /dev/null
+++ b/cloud.md
@@ -0,0 +1,6 @@
+Cloud characteristics:
+
+Multitenancy
+Elasticity
+Scalability
+Portability
diff --git a/linux/linux.md b/linux/linux.md
index 43ef7d0..8dd5f4d 100644
--- a/linux/linux.md
+++ b/linux/linux.md
@@ -262,8 +262,33 @@ https://static-course-assets.s3.amazonaws.com/CyberEss/ru/course/files/5.1.2.4%2
 head -c 24 /dev/urandom | base64
 ```
 
+### Environment Variables
 
-
+Setting an Environment Variable
+```
+export JAVA_HOME=/opt/openjdk11
+```
+Unsetting an Environment Variable
+```
+unset JAVA_HOME
+```
+Listing All Set Environment Variables
+```
+set
+printenv
+env
+export
+export -p
+cat /proc/$pid/environ
+```
+Persisting Environment Variables for a User
+```
+vi ~/.bash_profile
+```
+Setting Permanent Global Environment Variables for All Users
+```
+sudo vi /etc/profile.d/http_proxy.sh
+```