Html sites are single linked html pages, cheap and quick to build, whereas CMS sites are interlinked dynamic database driven systems, more expensive to set up – but they are cheaper and quicker to update in the long run.
And now, as of April 2015, another reason to by pass html sites, is that you will be penalised in Google Directory for having an html site, if it is not google mobile friendly. You may be planning to upgrade your html website to a CMS, or you have no website and want to get the best site for your needs, right from the start. The reason why people opt for a CMS, (Content Management System) is because they like to be able to quickly edit their content online, whereas with html sites, are not able to do that. An html website used to be sufficient for a Static Brochure type Website, and it was a cheaper option. However, from now on, you cant even consider this option. I would also strongly suggest that you upgrade your html site to a WordPress immediately, because Google is going to penalise all sites that are not deemed mobile friendly. And I hate to say it folks, most html sites are simply NOT mobile friendly, hence your site will go to the bottom of the search. Just run a search in google for testing your site to see if it is mobile friendly: https://www.google.com/webmasters/tools/mobile-friendly/
WordPress.com or WordPress.org?
A basic blog account at WordPress.com is free; but will only give you limited functionality, not able to add plugins for things like newsletters and join ups etc. This means its not suitable for a fully fledged website for business. When you enrol at wordpress.com you are given a domain name URL like http://www.myblog.wordpress.com, which most visitors can spot it is not a privately owned domain name. I have a http://www.webdesinz.wordpress.com blog, just to illustrate how it works. Of course, WordPress.com does have the facility to add a private domain name to mask your blog address, and replace it with a single private domain name; but because you have to pay for monthly hosting for that service, you might as well have your own independent site running separately in the first place. WordPress.org, is the place where developers can view then download the open-source free themes and plugins by the dozen, then build a WordPress site for you, with all the bells and whistles you desire. I am not suggesting a lay person try and do this themselves, unless they are a little bit savvy with developing already.
A privately installed wordpress, has no restrictions like what is encountered at wordpress.com, and this allows you hundreds of different functions. If you require a show case for your products or fully link to a Shopping Cart, then you can have either option with a WooCommerce Plugin. Therefore if you are in business then you should get a CMS installed on your own hosting account and get this done by a developer, so you can a) can manage and edit it and b) extend the functionality later, without re-writing the whole site. If you are local to me you are welcome to come to my home office, I can teach you how to get around the admin dashboard area to your media library, your pages and posts, add galleries and upload documents or whatever functions you want added. Contact www.webdesinz.com for more advice on upgrading your website.