According to the Wordpress website.
"WordPress is web software you can use to create a beautiful website or blog. We like to say that WordPress is both free and priceless at the same time."
A CMS is a content management system, this means once set up you can log on and edit and make changes. The website will then show those changes immediately. This is great for many users who want to or need to update their websites. You don't need to pay us to do this, you need little experience as editing a page is similar to editing in a word processor, and we can easily teach you to do this.
Therefore you can firstly update your website in real time when you need to and save money on having it updated!
Wordpress started life as a system for mainly blogging. However now it is one of the largest CMS systems used worldwide. Many major companies and projects use Wordpress and whilst for some it is not as "serious" as say Joomla or Drupal it is very polular and easy to use. A whole industry has begun to make great Wordpress websites that are easy from the user side.
While Wordpress is free it does need to be set up and set up properly, also there are some additions that you may want, like nice templates, slideshows etc and these can cost money as they are written by independent developers. But a lot of these item are relatively cheap.
So why do you need us? Well it needs to be set up, made secured and set to look and function how you want it to be. Also it needs to be set up to be found in the search engines or no one will see it no matter how good it is.
Once running, it will need maintaning, backups taken regularly, updated for security etc.