One thing we learned in reviewing the services listed here (and many more) is that even though the packages are very similar, they are not identical. Some are more security-focused than others, offering anti-spam and anti-malware tools. Others offer a variety of email marketing tools. While most of the hosts we've reviewed have built-in e-commerce, you may want to consider using a more-robust third-party online shopping cart application like Shopify instead.
A Content Distribution Network (CDN) is a network of servers distributed geographically. The purpose of a CDN is to deliver content on the internet much faster. If a user in Toronto is trying to access your website, the closest server to them will take care of this. But someone coming to your website from Sydney, Australia, will be catered to by a server closest to them. The main host server holds your website content, and all the other servers have a cached version each.
Unlike shared or VPS hosting, dedicated hosting makes your website the lone tenant on a server. To extend the housing metaphor, having a dedicated server is like owning your own home. The means that your website taps the server's full power, and pays for the privilege. If you're looking for a high-powered site—an online mansion for your business—dedicated hosting is the way to go. That said, many dedicated web hosting services task you with handling backend, technical issues, much as homeowners have manage maintenance that renters generally leave to their landlords.