<Ul> <Li> Intracloud (IC), which occurs within a single thundercloud unit </Li> <Li> Cloud to cloud (CC) or intercloud, which starts and ends between two different "functional" thundercloud units </Li> <Li> Cloud to ground (CG), that primarily originates in the thundercloud and terminates on an Earth surface, but may also occur in the reverse direction, that is ground to cloud </Li> </Ul> <Li> Intracloud (IC), which occurs within a single thundercloud unit </Li> <Li> Cloud to cloud (CC) or intercloud, which starts and ends between two different "functional" thundercloud units </Li> <Li> Cloud to ground (CG), that primarily originates in the thundercloud and terminates on an Earth surface, but may also occur in the reverse direction, that is ground to cloud </Li>

Where can lightning take place that is where can it begin and end