What is it?

A Web Content Management System (WCM, WCMS or Web CMS) is content management system (CMS) software, implemented as a Web application, for creating and managing HTML content. It is used to manage and control a large, dynamic collection of Web material (HTML documents and their associated images). A WCMS facilitates content creation, content control, editing, and essential Web maintenance functions.

The software provides authoring (and other) tools designed to allow users with little knowledge of programming languages or markup languages to create and manage content with relative ease.

How it works

The CMS systems use a database to store content, metadata, or artifacts that might be needed by the system. A presentation layer displays the content to Web-site visitors based on a set of templates: a set of html and css, javascript and other files.

Most systems use server side caching boosting performance. This works best when the WCMS is not changed often but visits happen on a regular basis.

Administration is typically done through browser-based interfaces.

Unlike Web-site builders, a WCMS allows non-technical users to make changes to a website with little training. A WCMS is primarily a Web-site maintenance tool for non-technical administrators.

Open source vs. licence based systems

Most CMS-s are open source, such as Joomla or Drupal, and they are distributed under GNU licence. They are completly for free and can be hosted almost everywhere, because they have minimal system requirements. While the full source code can be downloaded, the hackers can search bugs and may find security leaps. The other common problem is, that if you modify the source code it is difficult to upgrade to new version later. Or you must rewrite the full html/css template set, because the never version is incompatible with the older version.

A licence based CMS's source code and know-how in most cases is owned by the authors, and it is handled in a closed system. The source code can be never accessed by the customer or other persons. This reduces security risks.

Most system are running in several servers (separate database, back-end and front-end, cache, etc...) and have special hardware or software requirements.

Disadvantage that you can't host your webpage anywhere. But you get unlimited upgrade support, and you must not spend a lot of many for hardware, software and technical personal.