Answer:
threats can be internal and external.
Internal threats are like deseases that people get especially for workers in a factory, they will affect the business and a loss of workers will mean that the rest of the workers will have to do their work.It is something that happens within a factory, school,etc.
External threat is like Arab attacked Amerika and the 2 twin towers collapsed because of them. This kinnd of thing is called "Terrorism". It is something that ocurred out of the country.