Unmanaged hosting plans place responsibility for some administrative work on you as the customer. Managed hosting plans, however, leave the heavy lifting to the web-hosting service provider. Unmanaged is like if you hang your art in a gallery and you have to clean it, make sure it's hung right and generally maintain it. Managed is like gallery employees handling those tasks for you. Unmanaged plans are generally more cost effective, but managed plans free up your time to focus on your site.