A content management system, or CMS, is a piece of software that makes it easy to create and manage websites. It is very important for a website's content to be frequently refreshed and updated. Fresh content keeps visitors coming back and can improve search engine rankings. However, publishing new content on a regular basis can become complicated if the webmaster has to make a new HTML page each time he adds an article, image, link or other piece of content. Content management systems have been developed to solve this problem.

With a content management system, there is no need to create new HTML pages manually - the CMS does it automatically. The webmaster simply enters the content into a form, clicks a button and the software generates a new web page. A content management system separates the content (e.g. images, text, links, files, etc.) from the layout. When the webmaster sets up a new website he creates a set of templates for the pages. Whenever he adds new content, the pages are automatically laid out based on these pre-defined templates. This may sound complicated, but in most modern content management systems, setting up the templates is simple. The webmaster will probably use an HTML editor like Adobe Dreamweaver or Microsoft Expression Web to create templates for the CMS. They contain all the page elements that are common across the whole site like header, footer, logo, and navigation. Spaces are left in the templates for the CMS to insert content when a new page is generated.

Users who are not confident with HTML need not worry - most content management systems offer some ready-made templates that can be used 'out of the box'. Many open source content management systems offer free templates, which have been submitted by their community of users. It is also possible to buy CMS templates from online template stores. Another alternative is to find a designer to build custom templates.

These are the basic principles upon which all content management systems are based. So how do you choose which CMS is right for you? The first thing to establish is the size of your budget. Content management systems range in price from zero up to thousands of dollars. The no-cost end of the market is comprised of the many open source content management systems that are available. At the high end of the market are the custom built enterprise systems used by big corporations.

For the purposes of this article, we will concentrate on the open source options; there are so many CMS products to choose from in this category that there is bound to be one to suit most needs. Open source software has an open license, which means it is free to use and the source code is available for anyone to modify it.

Some of these open source systems are capable of running complex portal websites with lots of dynamic functionality, whilst others are much more simple. It is important to establish the scope of a website before choosing the CMS. Most websites exist simply to publish standard content. For sites like this, a complicated portal CMS is not required. (We will discuss portals in more detail later.)

Learning how to use a portal CMS can be quite a demanding task because of the complexity of these systems. For most simple websites there is no point in going through this learning process. Instead choose a simpler CMS that will require far less time and technical skill to operate. One of the simplest content management systems is called sNews. Other simple alternatives include most of the blogging software packages (e.g. WordPress, Nucleus, Typo, etc.). Although these are called 'blogs' they are, in fact, content management systems. By default, they have been configured to run blog sites, but by simply changing the templates they can be made to run many other types of website.

There are also many simple content management systems that are not primarily designed to run blogs. These systems will run a wide range of websites (including blogs!) and although the core software is usually fairly simple, there may be add-ons and plugins, which can be used to extend the system's capabilities. A good example of this kind of system is a package called 'CMS Made Simple'.

We have already briefly mentioned portal systems. As well as managing content, these provide all kinds of additional functionality like front-end user registration, polls, forums, ecommerce, mailing lists, etc. They are very powerful pieces of software and, for the advanced webmaster, they provide almost endless possibilities in site creation. However, for novice and intermediate users, the high level of technical ability required may be prohibitive. Examples of portal systems include Joomla!, Mambo, Drupal and Postnuke.

You should now have an overview of how content management systems work and some of the things to consider when researching which CMS to use. It is important to note that there are hundreds more open source content management systems than the handful mentioned here.