Themes are what make your website look pretty. They consider where to put the site’s title & menu(s). They consider what comes next – header image, featured content rotator, etc. They consider things like colors & backgrounds plus fonts. And they do this globally across the entire site. If you look at all my pages & posts you’ll see they’re all the same. The only difference will be images & what I’m writing about within the page or post.
Both WordPress.com & WordPress.org are all about WordPress. Within the backend of the software are links to both appearance (themes) & plugins (more features). At WordPress.com you’re limited even if you pay for it which is why I left them when I was paying for it. On your own hosted server you can install themes & plugins they don’t have at WordPress.
WordPress is such a popular software that others are creating themes & plugins for it & selling them on their own sites. I’ve bought a couple of themes. One included plugins that were paid for & the only way to update them was to sign in with the account info of the person who paid for them. That would be the theme creator but rather than giving me the account info he wanted access to my site so he could update them himself. I didn’t want to give him access so I got my money back instead.
Another was created for those who have a shopify shop. I had a shop. But it wasn’t a shopify shop. I didn’t know such a place existed. But you have to pay for your shopify shop. And I couldn’t so I couldn’t use the theme. The site I bought it from wouldn’t give me my money back, so I had to get my bank involved & I’ve never used them again. So just be careful while out shopping. 😉