Nearly every software company uses different environments for various stages of their code — local, development, staging, review, and production, to name a few.

For example, you might use a staging environment to host the app you’re about to deploy to production as you do one last spot check or run your test suite against it. Or you might use review apps as part of your code review process so that reviewers can easily confirm the app is working properly with the changes contained in the pull request.

Source: DZone