Fuzzing is a vulnerability testing process where the inputs of an application are tested with random data to identify bugs. The target being tested can be anything from Microsoft Word or Mozilla Firefox to a VOIP phone or network router. Companies like Microsoft and Juniper now use fuzzing tools, and the availability of many commercial and open source tools. The tools must be able to document and replay all previously run-test cases in order to determine which test caused an application to crash, or a network device to stop responding.”]
Source: https://www.darkreading.com/analytics/tech-insight-the-buzz-around-fuzzing