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.
SSL certificates are needed because they encrypt the data exchange between your website and the visitor’s browser, making it impossible for hackers to get access to this data. This is especially important if you store your customers’ credit card information. For a complete website hosting experience, HostPapa provides you with a Let’s Encrypt SSL Certificate completely free of charge!