samsung j7 2017 vs j7 2016

Why is Samsung Galaxy J7 (2017) better than Samsung Galaxy J7 (2016)? 9. samsung galaxy tab a8 09% more battery power? 3600mAh vs 3300mAh 1 5x higher pixel density? 401ppi vs 267ppi 1GB more RAM memory? 3GB vs 2GB 2 25x higher resolution? 1080 x 1920px vs 720 x 1280px 2 6x more megapixels (front camera)? 13MP vs 5MP Wi-Fi