Phones have Brand followed by a Series of model and then the model name or number.
Example of SAMSUNG Brand and Series are:
Samsung Galaxy J | Samsung Galaxy S | Samsung Galaxy NOTE | Samsung Galaxy A
| Samsung Galaxy Mini | etc…
Other models that have Brand and Series:
Sony XPERIA | Nokia Lumia | Motorola RAZR | LG Optimus | LG G series | Huawei Ascend | HTC U | HTC One | HTC Desire | BlackBerry Bold | BlackBerry Q | Google Pixel | Google Nexus
You will always find the exact model number in [Settings],[About] or on the back of device or under the battery.