This blog is a bit long in the tooth, there's a more recent blog about WordPress...
A story I often tell to describe a website is, imagine a website is a house. The bit of land the house sits on is your hosting space, the front door is your domain name and the letterbox is your email address. Those the parts make a basic website.
If you spend much time sharing photos and stories on social media for yourself or promoting a business, a big advantage of having a website (with WordPress) is that you have full control. With platforms like Facebook, Twitter or LinkedIn, sure there's massive traffic going to those sites, however, they can change what they show and how they show it. You don't have control over that.
WordPress is really good at categorising and archiving so it's far easier to go back and reference older content, and search engines like websites that cross-reference and backlink effectively.
With free services like wordpress.com, Wix or Squarespace, it's a real limitation. Imagine free websites as an infinite block of flats going up into the sky, and google is the postman. He's going to have a hard time finding you. Having your hosting space for your website is like a little patch of land, the postman can find you more easily, and you can run your own Search Engine Optimisation tools too.
Speaking of SEO, WordPress has a plugin called Yoast which guides you through the process of making your pages get seen easily by search engines.
Search engines don't like waffle and Yoast is very good at guiding you into condensing what you have written into something that search engines like Google or Bing will digest quicker.
Using WordPress should be a comfortable experience. If you're ok using computers in general you'll be fine with WordPress. The original intention of WordPress was a blog, to share photos and stories - it was designed for non-technical people - so if you're logging into your website and finding it very technical and hard to use - something's gone wrong in the design process.
Plugins are extensions that add to your website such as search engine optimisation but also features like event management and E-Commerce (woo-commerce) in which allows you to sell online. There's are thousands of plugins of varying quality, and it's up to the website developer to know the right plugins to use on a website and implement them properly.
One of the main bugbears I have personally is page builders. These are extensions to WordPress which allow for very impressive design but can make updating your website complicated and time-consuming - as they change the way WordPress fundamentally works.
There are good page builders out there and some really bad ones. If you're having problems updating your website, or find that it's fiddly or confusing, check with your web developer to see if you have page builders on your website and if they can be removed. At the time of posting this article, WordPress has released their own drag and drop Page Builder called 'Gutenberg' which in time will probably be the best of the bunch, but my advice is to go with what feels right for you.
Having your own WordPress website should be a user friendly and enjoyable experience you should enjoy putting projects onto your site and then sharing them under social media.