Definition of a “production” system?

Does anybody have a good, comprehensive definition of a “production” system? The IT leaders in our organization have unofficially limited it to just systems that directly interface with the customer. I.e., if the customer would immediately notice if it suddenly went down, then it’s production. Otherwise it’s not.

Since those systems are all Linux, our Active Directory environment isn’t considered production which seems crazy to me. We develop software, so would you consider our Jenkins pipeline to be production? What …

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