How are nokia phones categorized according to their models?

Question

what are the differences of nokia phones according to their models? why there are 6300 and 6300i or 6800 or 6600 6101 0r 6102? why or how were they categorized / named in models?

Answer 1

They categorized due to the different features they offer for example the 6000 series phones are S40 based and offer lower end features such as 2Mp Cameras and other basic features where as the N series phones offer advanced features and are S60 based and so on...