What, in essence, is ‘war’? ‘Definition’ considers various concepts of what war actually is and how commentators have tried to define it. There exist many different types of war, such as inter-state war, civil war, revolutionary war, imperial war, and religious war; they sometimes overlap with one another. War could be summarized as involving heterogeneous, organized, mutual enmity, and violence between armed groups, on more than a small scale, carried out with political objectives in mind, possessing socio-political dynamics, and focused on exerting power to overcome an enemy. What does ‘modern’ mean? It is difficult to define what is inherently distinctive about modern war.