Air Printing is a feature on mobile devices that lets you print from Android to printers wireless. There are many apps which support ePrint printers (in all brands, like HP, Brother, Epson, Canon, Samsung...) but when Google develops an app, it is really hard for others to compete.
Cloud Print developed by Google, provides the fastest way to print from your Android device to a Google Cloud Print connected printer.
You just need to select the document to print, and then tap Sharing button and select Cloud Print
To see if your printer is a Cloud Ready printer, see: Cloud Ready Printers.
Otherwise see, Connect your classic printers with Google Cloud Print