Your computer’s CPU comes from the factory set to run at a certain maximum speed. If you run your CPU at that speed with proper cooling, it should perform fine without giving you any problems.
However, you’re often not limited to that CPU speed. You can increase the CPU’s speed by setting a higher clock rate or multiplier in the computer’s BIOS, forcing it to perform more operations per second.
This can speed up your CPU — and therefore speed up your computer if your computer is limited by its CPU — but the CPU will produce additional heat. It may become physically damaged if you don’t provide additional cooling, or it may be unstable and cause your computer to blue-screen or restart.
So basically it's simple that you get more...