Production is the live site, for the most part. The production site can be used for user acceptance testing (UAT) after QA and regression testing has been completed, but typically UAT occurs on staging.
Some code, like payment processing, requires testing on production with real credit card credentials. Merging to “master” and deploying to production tends to be a controlled exercise for our team.
Some of our project partners have a weekly standing deploy time where our devops team member will oversee the push. Then, the rest of the team can test to ensure nothing broke. If and when this happens, we already have people’s attention to quickly assess and fix the issue.