After the many speculations and rumors, finally Apple launch its two new iPhone model-iPhone 6 and iPhone 6 Plus. According to rumors, both handset released with too large size as compare to its previous iPhone models. As well as more features and specification introduces in both devices.
Both iPhone are top tier phones. There are only three major difference between those handset:
1. Screen Size
2. Battery
3. Resolution
But there are more distinction, apart from these major differences in both smartphones, which we explained here in detail:
Design:

iPhone 6: curved aluminium, gold or light/dark silver, 6.8mm
iPhone 6 Plus: curved aluminium, gold or light/dark silver 7.1mm
Both phones are made of aluminium, with a steel Apple logo for that extra bit of hardness, and a toughened glass front (one with Ion reinforcement apparently). Apart from this iPhone 6 Plus is much larger and tiny thicker as compare to iPhone 6.
So in designing part choice is iPhone 6 Plus, because most of peoples prefer larger size and more slimmer smartphones.
Screen:
iPhone 6: 4.7-inch 1334 x 750, “Retina HD” LCD
iPhone 6 Plus: 5.5-inch 1,920 x 1080 LCD, optimisation in landscape
Last few years, Apple offered small screen size in their iPhones as compare to Android devices. But now iPhone announced with larger screen size just like Android smartphones.
iPhone 6 Plus announced with 5.5-inch screen size, whereas iPhone 6 has 4.7-inch which is less smaller as compare to iPhone 6 Plus. Further more resolution and pixel density is higher in the iPhone 6 Plus. Where the iPhone 6 has a display of 326ppi just like the its predecessor iPhone 5S.
Again iPhone 6 Plus is better option as compare to iPhone 6.
Processor:
iPhone 6: Apple A8 64-bit
iPhone 6 Plus: Apple A8 64-bit
Both devices have the same new processor A8. Apple says that the new A8 processor offers 20 percent higher CPU performance and 50 percent GPU performance than A7.
RAM and Storage:
iPhone 6: 16/64/128GB and 1GB RAM
iPhone 6 Plus: 16/64/128GB and 1GB RAM
New iPhones models do raise storage capability from 16 GB to 128 GB. You can get any model between 16 GB, 64 GB and 128 GB with holding 1GB RAM.
Camera:

iPhone 6: 8MP camera, 1/3.06-inch sensor, true-tone flash,f/2.2 aperture dual-LED flash, phase detection
iPhone 6 Plus: 8MP camera, 1/3.06-inch sensor, true-tone flash,f/2.2 aperture dual-LED flash, phase detection, OIS
Both new handset uses 8-megapixel sensor with 1.5 micron sensor pixel, a dual tone flash and lens of f.2.2 aperture. There we are slightly disappointing, Apple has not really changed the camera quality in iPhone 6 and iPhone 6 Plus. Sensors has been redesigned but core specs are pretty similar as its predecessor iPhone 5S.
The difference between both handset is that iPhone 6 Plus offers optical image stabilization and will be able to take a much better low-light pictures, where iPhone 6 uses software stabilization.
Battery Life:
iPhone 6: 11 hours video, 11 hours browsing
iPhone 6 Plus: 14 hours video, 12 hours browsing
This year, we can see that iPhone 6 make a slight difference in their battery life as compare to iPhone 5S.
Conclusion:
Apple’s new models gives us a pretty consistent experience with greater size, good quality camera higher pixel density etc. iPhone 6 Plus, much larger display, better camera, good battery life becomes more powerful device as compare to iPhone 6. So choose which is pretty well according to your budget.