Wiki · Reference entry
Sandbox
A copy of the environment where actions do not really happen.
Essential and insufficient. A sandbox tells you the mechanics work. It cannot tell you what real data looks like, how real users behave, or which of your policies your actual systems disagree about. Most of what kills a deployment lives specifically in the difference between the sandbox and production.
Why it matters
Passing in a sandbox is the beginning of the evidence, not the end.