Apart from the design difference - the biggest difference is AirPods are wireless while EarPods are not wireless. The AirPods comes with lot more openings compared to EarPods.
AirPods usually deliver about 5 hours of listening time one one single charge.
Yes, you can use Apple Airpods with any Android mobile phones, which has at least Bluetooth 4.0 connectivity option.
It is very very easy thanks to seamless integration, which Apple has done. All you have to do is to bring your AirPods case near to your iPhone and open the AirPods case. The moment you open the AirPods case, your iPhone will detect it and will give you prompt to connect like the side image. Tap the connect button and you are done. Your AirPods are connected with your iPhone and they are ready to use.
Yes, you can connect Airpods with iPhone 6.
Look past their offbeat design and you'll find that Apple AirPods' compact size and high convenience factor are a winning combination.