The ZZ method was invented in 2006 by a Polish speedcuber called Zbigniew Zborowski as an efficient (for speedsolving) and ergonomic blockbuilding/LBL method for the 3x3 Rubik's cube.
Since then, a small but growing community has slowly built around it and many variations of the method have been developed, with possibilities still being explored.
The ZZ method can be used to solve a cube in 3-4 steps and an average of 45-60 moves depending on the variant. The defining feature of the ZZ method is that the first step always features Edge Orientation (EO).
Edge Orientation is a technique of changing the edges to a state where they do not require F/B or wide moves to be solved, so that the cube can be solved with purely R, U, L and D moves. The most basic ZZ steps are: