A domain name is the bit of the URL (the long address in your browser’s search bar) that identifies a web page — in this case your website. You can register them separately at sites like GoDaddy and Namecheap, but website builders offer to do it for you when you sign up with them. Most provide it for free (at least initially), while a handful charge a few extra bucks.
If you are going to use a website builder you can usually purchase it there. That makes handling it slightly easier as you’ll only be dealing with one company. If you are going to use WordPress or you’ll be programming the website yourself, you will also need web space, where you can upload your website’s files and data. With a website builder you don’t need web space as it’ll be already included.
Thanks for a great review! My only “con” would be that you didn’t included customer service. But I understand the work it would have involved. I LOVE WIX. I have been with them since they started. But their customer service stinks. I don’t like having to search through a database of questions other users have submitted to find an answer to my problem. They make it hard to find a phone number. Otherwise, besides a few technical beefs I have, it is a great option.