Content Management System. This is a platform that you would install into your website. You would then use forms to fill out the content of your pages. Most CMSs will have at least a page title, and the content all in one form. You would fill out the information with just clicking and selecting fields, and when everything is the way you would want it, you would select save or publish. In Word Press, it is Publish. I don’t know of how any other CMS systems will function.
All CMS platforms will require server programming such as PHP, and at least 1 MySQL database. In example, each one of my domains have its own database, and I use the subdomain for the table prefix. In example, the prefix for this site is terms_. This makes management so much easier, and allow you to know what tables should be deleted if you shut down a particular website. You would need to have all of the information required for the CMS to properly align itself with the proper database, and inserting the content where you want. I will typically keep the .php file for each domain, as a file on my computer. That file will be modified for the website’s particular table, and I will upload that edited file to the website which will make installation for future sites so much easier.