The original iPad Air models have the same 9.7" Retina display as the earlier iPad 3rd Gen and iPad 4th Gen lines, but are "20 percent thinner and 28% lighter" and have a much narrower "bezel" around the display, which makes the iPad Air "feel" quite a bit smaller than its predecessors.
All iPad Air devices feature a 9.7" 2048x1536 (264 ppi) LED-backlit IPS touch-sensitive display, a dual core 1.4 GHz Apple A7 processor and 1 GB of RAM.
Other notable features include dual cameras -- a rear-mounted 5 megapixel "iSight" camera capable of shooting stills and 1080p video and a front-mounted 1.2 megapixel "FaceTime HD" camera capable of shooting stills and 720p video. Connectivity to computers, if desired, and power is provided by the Lightning port.
Supported iOS Versions for iPad:
iPad 1 - iOS 5.1.1
iPad 2 | 3 | Mini 1 - iOS 9.3.5
iPad 4 - iOS 10.3.3
iPad Air 1 | Mini 2 | Mini 3 - iOS 12.x
Other models update to the current version of iOS