These supercomputers are incredibly powerful. They are made up of giant mainframes linking tens of thousands of processors to achieve incredible computing speeds, measured in petaflops. One petaflop equals 1 quadrillion calculations per second. For comparison, that's more than 12,000 times faster than a MacBook Pro.

The United States is currently home to the world's fastest supercomputer, Sequoia, according to the Top 500 List. The Sequoia supercomputer, housed at the Department of Energy's lab in California, reached a speed of 16 petaflops when it was ranked in June.

Another American supercomputer, called Titan, which can hit a peak of 20 petaflops, is on track to dethrone Sequoia as the fastest machin0Titan replaces Jaguar, which is ranked sixth on the latest list.