That's the actual codename; these are often based on at least one of these factors:
1) Architecture; e.g. NetBurst had the Prescott and Core has the Conroe
2) Process; this is the size of the die where most of the processing does on, some are 90nm, some 65nm and soon 45nm
3) Cache; the cache on some models is different, such as the E4300 which is an Allendale and the E6600 which is a Conroe.
The actual place of origin is on the CPU itself.