1xxx – bare bones model.
2xxx – entry level with color screen, and maybe a camera.
3xxx – entry level with more features than 2xxx series device.
5xxx – music centric series.
6xxx – mid-range series, good number of features.
7xxx – low to mid-range fashion centric series.
8xxx – high end fashion phones, with strong emphasis on design and materials.
9xxx – communicator series, phones with full keyboards.
Cseries – represents the core range of products.
Eseries – business centric series.
Nseries – the ultimate in multimedia devices.
Xseries – focuses on social entertainment.

Credits