Enlist the differences between variable name and...

Variable Name	Environment variables
To build variable names, you need to add strings.	To access environment variables, you have to access existing variables.
It allows adding more strings.	We need to see advances playbook section to set environment variables.
We use the ipv4 address for variable names.	We use {{ ansible_env.SOME_VARIABLE }} for remote environment variables.
{{ hostvars[inventory_hostname][‘ansible_’ + which_interface][‘ipv4′][‘address’] }}	# … vars: local_home: ” {{ lookup(‘env’,’HOME’) }}”

Enlist the differences between variable name and environment variables.