What is a world war and how many world wars have happened so far?
World war is an international conflict that involves most major countries. There have been 2 world wars so far.
Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request.
### Instruction: What is a world war and how many world wars have happened so far?
### Input: 
### Response: World war is an international conflict that involves most major countries. There have been 2 world wars so far.