[garysahota93]

It's a great question!

A sandbox is a testing environment that isolates untested changes & experimentations from the production environments.

Chances are if you're using Salesforce for work, it's the "production" instance that is meant for prime-time. There is probably some admin/developer/IT person in your company that has access to creating sandboxes to test changes before they push to everyone else.

fwiw typically this is used by larger companies & isn't as useful for small startups.