Most companies have things that run "in dev", "in staging", "in CI", and "in production". These map directly to some tools - for example, React has "development" and "production" modes. When someone says a server or a database or a tool is used "in production" they're usually referring to the live environment that users access. Most people use tools like Webpack locally to run code when they're doing dev work, and in CI to build things. If someone said to me "We're running Webpack in production" then I would have questions.

If you use "in production" to mean "anywhere in a project", then how do you differentiate between a staging environment and a production environment? Do you talk about "the staging environment that's in production"? That would be confusing...