Node.js: How does process.env differ from global?

Question

How is setting an environment variable like process.env.thing = 42 different from creating a global variable like global.thing = 42?

When would prefer process.env.thing over global? What are the pros/cons of both objects?

Answer 1

global is the global object. process is available globally, because it is a property of global. In fact:

global.process === process //-> true

process.env has properties set to the environment variables of the system. These can be set a variety of ways outside of node itself, and read in by accessing properties of process.env.

At the command line try:

FOO=bar node -e "process.env.FOO"

The process module is just a globally available thing.