I never thought of looking for this, but it suddenly appeared in front of me, quite literally. There is a logical way that Nokia names their phones. Sometimes we feel that phone from a series don't fit and don't match and think that Nokia just felt like putting both phones in one category, well atleast I think like that. Turns out I'm wrong, there is an actual criteria for naming phones.

So...

Nokia 1000 - Ultrabasic series: These are the cheapest ones around, and definitely the most succeeded. The 100 sold over 250 million pieces.

Nokia 2000 - Basic series: Entry-level phones just slightly better in features when compared to the 1000s.

Nokia 3000 - Expression series: My first phone was a Nokia 3330, the only expressional feature about it was the Xpress-On covers that I could change every day and try out new combinations. These phones are targeted towards young males.

Nokia 5000 - Active series: If you think about phones such as the 5100, or the well-succeeded 5210, those are tough and durable devices, although some don't fit in this category in my opinion, such as the 5310 XpressMusic.

Nokia 6000 - Classic Business series: This one isn't very complicated to understand. They are all slick phones, or atleast most of them. My second phone was a 6600, and it is surely dedicated to business.

Nokia 7000 - Experimental series: I just spoke about the new Supernova collection, and it's definitely centred around the 7000s because it's a new series. The same happened with the Prism and the 7280, which had a curious design. The 7650 was the first Nokia Symbian S60 phone. The 7610 was the first phone with a megapixel camera. The 7710 is one of Nokia's few touchscreen devices, and has a backcover-built-in DVB-h receiver.

Nokia 8000 - Premium series: Not much to discuss here. The 8310 might not look very premium but when it came out it was rare and super-expensive, I remember staring at it as I never saw such a small and sexy device in my life. The 8800 Arte was reviewed not long ago by us.

Nokia 9000 - Communicator series: The QWERTY clamshells have been discontinued and are now included under the ESeries. We have just reviewed one, and it's the E90 Communicator.

Nokia ESeries: The Enterprise phones. All devices that are focused on business and run on S60.

Nokia NSeries: These are multimedia computers of all form factors and different focuses. My third and current phone is the Nokia N95, which is an example.

Nokia NGage: Only two of these phones were launched, and now the NGage gaming platform is included as software in some NSeries devices.

Source: Wikipedia via The Gadget Blog via Textually