In 1974, Erno Rubik invented the world's first Rubik's cube. After initially scrambling it, it took him over a month to solve it for the first time. He was initially designing the Rubik's cube to show his students at the time that something could be built out of pieces that all moved independently of each other. Though it seems like a simple enough puzzle, the 3x3x3 Rubik's cube has 43 quintillion solvable states and countless unsolvable states. Rubik's brand has created a beginners pdf method to solve the 3x3x3 which can be found here. Most people know about the standared 3x3x3, but there are cubes ranging in size from a 2x2x2 up to a 33x33x33.
Speedcubing is when someone uses algorithms to solve a Rubik's cube as fast as they can in a race against the clock. There are many different methods of solving that have their own styles and algorithms for each cube, but for a 3x3x3 cube, there are 3 main speedcubing methods: ZZ, Roux, and CFOP, while Petrus method used to be another main method, it is rarely used now. The currrent world record for the 3x3x3 cube is 3.75 seconds and it is held by YuSheng Du, while there are videos and accounts on the internet that show some of the world's consistently best "speedcubers" either matching or beating this time unofficially. Another big part of speedcubing is cube notation so algorithms can be read, a helpful guide to cube notation can be found here
Do you think you know the Rubik's cube?