Intel's Sandy Bridge Core i7 2600K name explained
 

You will know that it’s a Sandy Bridge if you see a name with four digits starting with a number two. Number two in 2600 is the generation indicator meaning that this is the second generation of Intel’s Core architecture.

The 600 is the SKU numeric digits that will tell you which CPU you are getting and of course once again bigger numbers mean a better CPU. The suffix K tells you that the CPU is unlocked and the other iterations such as suffix S will tell you that this is a CPU with performance optimized for lifestyle computing and T has Power Optimised Lifestyle whatever that would mean.
http://www.fudzilla.com/processors/p...name-explained