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.
Since 2015, Google Directory requires all websites to be https, (secure). You can still have an html site, but the hosting must be set up as a secure HTTPS site. 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. So, keep your HTML site, make sure it is secure, or upgrade to a WordPress site and get a developer to configure it securely.
The reason why people opt for a CMS, (Content Management System) is because they appreciate being able to quickly edit their content online, whereas with html sites, are not able to do that. A developer will have to do this for you, if you don’t have the skillset to edit and upload pages to a hosting server. There is also a question of the old type html sites not being mobile friendly, and if that is the case, 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 subdomain 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 showcase for your products or fully link to a Shopping Cart, then you can have either option with a WooCommerce Plugin. Therefore if you are requiring an extensive website for your business, then you should get a CMS installed on your own independent hosting account and get the site built by a developer, then 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.