iPhone 7 and 7 Plus
The 7 and 7 Plus are an incremental upgrade over the 6. The design is largely the same with the exception of a different antenna layout and an attempt to make the camera lens bump a bit less obtrusive.
The 7 series' biggest upgrades are in the camera. The 7 Plus has two lenses that allow for greater depth of field, optical zoom, and optical image stabilization. Both 7 models also come with the A10 chip processor.
We can't forget the most controversial change: This iPhone series dropped the headphone jack, an industry first that others are now emulating, much to users' despair.
SEE: Apple iOS 13: A cheat sheet (TechRepublic)