CORE 2

It is abbreviated as C2, the Intel Core 2 is a family of processors first introduced with the release of the Intel Core 2 Duo processor on July 27, 2006. The Core 2 processors include the Core 2 Duo (C2D), Core 2 Extreme (C2E), Core 2 Quad (C2Q), and Core 2 Solo.
The Core 2 Extreme was first released on July 29, 2006 and has 4MB of shared L2 cache like the Intel Core 2 Duo but has a higher clock speed and much more capabilities to be overclocked.