If you want to learn the iPhone model, first look at the back of the iPhone; You will see an expression of the model Axxxx. This is where you can learn your iPhone model. Users using iPhone 5 and iPhone 5S, or those using iPhone 6 or iPhone 6S, are known to mix phone models in some cases; but this process is removing it.
First, let's see which model number corresponds to which iPhone model:
iPhone X
Year to market: 2017
Capacity: 64, 256 GB
Colors: Silver, space grisi
Model number: A1865, A1901, A1902
iPhone 8 Plus
Year to market: 2017
Capacity: 64, 256 GB
Colors: Gold, silver, space grisi
Model number: A1864, A1897, A1898
iPhone 7
Year to market: 2016
Capacity: 32, 128, 256 GB
Colors: Black, black, gold, pink gold, silver, (PRODUCT) RED
Model number on back cover: A1660, A1778, A1779
iPhone 7 Plus
Year to market: 2016
Capacity: 32, 128, 256 GB
Colors: Black, black, gold, pink ...