iPad Air
iPad Air 1st Generation
The iPad Air 1st Generation, also called the iPad 5th Generation, was released on November 1, 2013, and was released with iOS 7.0.3, although it is limited to iOS 12.4.6.
It came in 16, 32, 64, and 128GB Models, each with 1GB of LPDDR3 RAM, and a Apple A7 System on Chip, with a PowerVR G6430 GPU.
iPad Air 2
The iPad Air 2 was released on October 22, 2014, and featured a Touch ID sensor.
It was released along with the iPad Mini 3, and iOS 8.1, which is upgradable to the latest version of iPad OS 13. It comes in 16, 32, 64, and 128GB Models, each with 2GB LPDDR3 RAM, and an Apple A8X System on Chip. The iPad Air is also the first iOS device to have more than 1GB of LPDDR-type RAM.
iPad Air 2019 Model
The iPad Air 2019 Model, also known as the iPad Air 3, was released on March 18, 2019, and featured a faster Apple A12X Bionic Chip.
It comes in 64 and 256GB Models, each with 3GB LPDDR4X RAM. It was released with iOS 12.2, and is compatible with the latest version of iPad OS.