Database update

Hello

Some news bulletin sites periodically send us a number of recent publications, which I did not understand. How can these sites update their database?

1- Is it through a special interface (requires access) for the article to be written and then put into the database?

2- Through a special link, he can access the database to add data to it?

The thing that I want to understand is what is the working method that I can update the database in a hidden way, that is, if the user subscribes to a site, do I create interfaces (requiring access) and here I can access as an admin, but the rest of the users cannot access because they have the authority of a user??

Or is there another way that I can update the database directly without the need for authentication? What are the risks of the two methods?