You can use AirPrint to send print jobs over a wireless network to compatible printers.
What is Apple AirPrint?
AirPrint is a mobile printing solution included with the Apple iOS
There are hundreds of printers with support for AirPrint. Most HP printers released in 2010 and later support AirPrint.
Apple maintains a list of printers across vendors here: Apple AirPrint
What are the requirements to print with AirPrint?
Make sure that you meet the following requirements to print with AirPrint.
- A printer that support AirPrint
- A private wireless network.
The iPad and the printer must be connected to the same private 802.11 wireless network. AirPrint uses Bonjour, Apple's zero-configuration networking, to automatically discover your wireless printer over the local network.
AirPrint is not supported through public wireless networks such as public Wi-Fi hotspots, Bluetooth connections, or on cellular 3G or 4G data connections.
More information
HP Printers - Printing with Apple AirPrint (iOS)