JAVASCRIPT

PROCESS.env

process.env.HELLO

process.env.production

export NODE_ENV=production

# Or if you are in windows you could try this:

SET NODE_ENV=production

process.env type

> typeof process.env.SOME_ENVIRONMENT_VARIABLE
'string'

what is process.env.node_env

"NODE_ENV is an environment variable made popular by the 
express web server framework. When a node application is run,
it can check the value of the environment variable and do different
things based on the value. 

NODE_ENV specifically is used (by convention) to state whether 
a particular environment is a production or a development environment.
A common use-case is running additional debugging or logging code 
if running in a development environment."