getenv() vs. $_ENV in PHP

Question

What is the difference between getenv() and $_ENV?

Any trade-offs between using either?

I noticed sometimes getenv() g

Answer 1

Taken from the PHP docs:

This function is useful (compared to $_SERVER, $_ENV) because it searches $varname key in those array case-insensitive manner. For example on Windows $_SERVER['Path'] is like you see Capitalized, not 'PATH' as you expected. So just: