Size difference/similarity in iPad Air/2

The iPad Air 2 from 2014 had Touch ID and an A8X chip. The iPad Air from 2013 had an A7 chip. The camera was also improved in the second version. For the full specs, see here:

• iPad Air (2013): https://support.apple.com/kb/sp692?locale=en_US
• iPad Air 2 (2014): https://support.apple.com/kb/sp708?locale=en_US

iPad Air 2 has 2 GBs of internal RAM.

The original 2013 iPad Air only has 1 GB of internal RAM.