What does OC mean in the name?

[LiquidAurum]

I know it means "overclocked" but what does THAT mean, does that mean that you CAN overclock it or that it's already overclocked? And if so overclocked from what? Overclocked from the reference card? Like for example in the link provided is an MSI 780 OC ediiton. It says it's core clock is 954 Mhz and it's boost clock is 1006 Mhz. What's the boost clock is that after you overclock it?

http://www.newegg.com/Product/Product.aspx?Item=N82E16814127746

 

[Gam3r01]

In the title of the card, OC mean it runs faster than reference speeds. Almost all 3rd party card run at an OC speed. These out of box speeds however have no impact on how YOU can OC it, for the most part.

 

[mazooni]

Stands for overclock. Like Game3r01 said almost all 3rd party cards are oced at least a little out of the box. Most 3rd party cards tend to overclock a bit better than reference designs but that is not always the case.

 

[JaredzzC]

OC means that it has already been overclocked by the company, but you are still able to overclock it more if you wish.
Boost clock, as far as I'm aware, means that it will run faster for you if necessary.
You could be playing a demanding game and in need of more power, so you system will detect this and your GPU will increase its clock speed by itself to give you slightly more performance.