System property value

System property value 

 They are contained only within the Java platform. 

 Environment variables are global at the operating system level. 

 You can set system property value via CLI using -Dpropertyname=value 

 You set environment variable using export envName=value 

 You can get system property value using System.getProperty(String key) 

 You can get environment variable in java using System.getenv(String anem)