One of the questions I am most frequently asked is what is hosting and how does it differ from the purchase of your domain. I swear they make some of these things confusing on purpose!
A domain is the address where your site can be found. You can purchase a domain from a lot of different places (Siteground, Namecheap, Google). There is a cost to purchase the domain that recurs on an annual basis.
ManagedWordPress Hosting sets up the place where all the files, posts, pictures, etc for your site will “live”. Imagine it as the storage area for all the fabulous things you plan to post for the world to see and enjoy! There is an annual recurring cost for hosting as well that varies depending on the amount of space you need and other features.
Your domain and hosting can be purchased separately, but I would recommend they be purchased together if you can (they often throw in the domain for free the first year with a hosting purchase).