Cyberwarfare is computer- or network-based conflict involving politically motivated attacks by a nation-state on another nation-state. In these types of attacks, nation-state actors attempt to disrupt the activities of organizations or nation-states, especially for strategic or military purposes and cyberespionage.

Although cyberwarfare generally refers to cyberattacks perpetrated by one nation-state on another, it can also describe attacks by terrorist groups or hacker groups aimed at furthering the goals of particular nations. It can be difficult to definitively attribute cyberattacks to a nation-state when those attacks are carried out by advanced persistent threat (APT) actors, but such attacks can often be linked to specific nations. While there are a number of examples of suspect cyberwarfare attacks in recent history, there has been no formal, agreed-upon definition for a cyber "act of war," which experts generally agree would be a cyberattack that directly leads to loss of life.