Abstract
An incident is usually defined as an event that is either unpleasant or unusual. In the area of cybersecurity, defining an incident and its category is conditioned by the consequence of its occurrence. The article discusses the notion of an incident and its categories introduced by the National Cybersecurity System Act. When describing the notions, the author also presented the requirements as regards incident reporting as well as issues concerning incident service and management, including the use of cloud computing services. In conclusion, it has been stated that the new definitions of telecommunication and cybersecurity incidents, which have been added on the occasion of subsequent amendments of legal acts, need to be made more specific.