How does *your* company go from writing code to production code to production software?

When you're working for a company and your pull requests are approved, how is the code integrated to the production software? As far as I know, it's now on the main branch, but how does that code reach the users?

Are there any sources online that cover what practices, or processes, that companies follow on how they work with production code? (Which may vary depending on their software development process.)

Do you just have a local repository at your production server that pulls from the main branch on the remote repository on a scheduled basis?

Or is it the same as mine, have someone that just manually copies code from the main branch to the server and run scheduled tasks to run each script?

I have to ask, as these questions have been festering in my mind for quite some time.

At my small-ish company (I'm the only developer, IT guy, Help Desk, etc.), all code is written and pushed through git and any code / script changes pulled to the main branch is manually copied over, by me, to our production server. At our production server, I just have a task scheduler that runs these scripts on a scheduled basis.

I'm sure this isn't the norm and I want to ensure the process I'm using to produce and push code is the standard way of doing things, however I can't find any sources online that show how this works?