Kernel mode, also referred to as system mode, is one of the two distinct modes of operation of the CPU (central processing unit) in Linux. The other is user mode, a non-privileged mode for user programs, that is, for everything other than the kernel.
In case you haven't had enough of the Harlem Shake, that 30-second meme that took over the Internet in early February, you can now tell YouTube to perform its own version of the dance. Just go to YouTube and search for do the Harlem Shake, then wait for a few seconds. The YouTube logo will start bouncing to the beat, and once the bass drops, the page will just basically explode. Hit the pause button if you want to disable the function. Interestingly, you can still click through to the various Harlem Shake videos that come up in search, even after the page freaks out.
All of the group did a single dance when they flop on the floor like a fish that they called the Harlem Shake The song they were dancing to was the same song every one uses now, but the lyrics (the few lyrics, I should say) had been added in since the popular video emerged.