Like every other software program that you use, it is wise that from time to time to update the software that allows you to post articles on your blog or site, which is WordPress. The system is updated, but it depends on you if you select to upgrade the latest version that you have with the version which was released in this day. You are notified every time WordPress is updated and it is up to you to update the system as well.
If you are using WordPress day by day, then you will see on the Dashboard page that you have to switch to another WordPress version, the newest one. This is happening because a new functionality is released or because a new upgrade of the security has been performed. When you do this, you have to make sure that you have the techncial requirements needed by the newest version, in case you are hosted on your own server or you better consult with the Web host, where your site is hosted, so that you will upgrade the platform without any worries at all. You need to do this because there are some PHP and MySQL versions, that run on the server, which might not be compatible with the newest version of the WordPress platform.
Then, before upgrading, it is wise to make a backup at your database. If you have writers that have the admin powers over the site, they are not able to do this. Only the owner of the site can do this, and usually it is super-admin, which means it is greater that the administrator of the site. Or if you are the admin and the writers have only powers to write posts, then most likely they will not be able to modify a thing there. They will not be able to moderate the comments, to change the articles if they have done somwthing wrong and they want to modify and so on. The upgrade of the platform should be done only by the admin of the site, by the owner.