"Test cricket is the most traditional format of cricket where each match takes place over up to 5 continous days, with about seven to eight hours of play on each day.
The World Test Championship (WTC) is a two year league based championship that involves the top 9 ranked teams playing bilateral test cricket, with each team playing an equal pre-determined number of home and away series. The top 2 teams at the conclusion of the league stage play the WTC finals. There is no promotion or relegation mechanism for the WTC. Currently, test cricket follows the WTC format.
Recently, the International Cricket Council (ICC) also discussed an alternate plan to streamline test cricket into 2 divisions of 6 teams each, with the top 6 teams forming the first division and the next 6 teams forming the second division. The "two tier system" as described above would have a promotion and relegation mechanism similar to that of club football."