Think of your smartphone as a mini computer – especially when you're accessing your favorite stores through an App. Have you ever asked yourself how the data from your device is transmitted to this store? Yes, the Internet is involved – but it is some type of Cloud service that is connecting the two of you in making the transaction. This holds true for mobile printing. The Internet connects you to the Cloud service that takes your data and sends it to the printer of your choice. When you use your smartphone or other Cloud-based services, such as email, you're probably using the public Cloud. You can use the public Cloud to print from your mobile device too.
Despite its name, the public Cloud doesn't mean that anyone on the Internet can see your print jobs. You can think of it as a community Cloud or shared Cloud. It is simply a shared infrastructure that supports multiple clients, and you can access it via the Internet. Typically, public Cloud solutions are hosted offsite by a Service Provider.