World War I, which lasted from 1914 to 1918, was one of the largest and most devastating conflicts in human history. The origins of this war can be traced to a variety of factors, including interstate rivalries, complex alliances, and nationalistic tensions. Two main alliances emerged: the Allies, consisting of Britain, France, Russia, and later the United States, and the Central Powers, represented by Germany, Austria-Hungary, and the Ottomans. One of the main causes of this conflict was the assassination of Archduke Franz Ferdinand of Austria on June 28 1914. This event triggered a series of declarations of war between allied countries. Tensions in Europe have been increasing since the late 19th century, primarily due to shifts in economic and military power. Industrial competition, colonialism and the arms race also worsened the situation. The impact of World War I was far-reaching and multifaceted. Politically, this war resulted in major changes in the map of Europe. Powerful empires, such as the German, Austro-Hungarian, and Ottoman Empires, collapsed and were replaced by new states. For example, Czechoslovakia and Yugoslavia emerged as a result of this process, creating new challenges in geopolitics. The world economy is also experiencing significant changes. This war caused huge economic losses for many countries. War financing and recovery costs resulted in inflation and rising national debt. On the other hand, the United States emerged as a leading economic power after the war, occupying an important position in global trade. In the social aspect, World War I created dramatic changes in the structure of society. Women, previously marginalized, began to play a more active role as many men went to war. This was the first step towards women’s voting rights in many countries. Additionally, the psychological impact of war brings deep trauma to many veterans and the families of lost members. The consequences of World War I are also visible in official documents, such as the Treaty of Versailles. This agreement not only focused on recovering losses but also set very harsh conditions for Germany, which indirectly fueled dissatisfaction and resentment. This was one of the factors causing World War II. Culture and art were also affected by the war. Many artists, writers, and thinkers responded to the experience of war through works that explored themes of loss, emptiness, and absurdity. This period is known as the Post-War Era, which gave birth to new movements and trends in literature and art. In an educational context, World War I paved the way for more critical and complex historical learning. Understanding the importance of conflict resolution and international cooperation is being given more attention. International organizations, such as the League of Nations, were founded in an effort to prevent the recurrence of similar tragedies. Overall, World War I was not simply a military conflict; it was an event that shaped the modern era with impacts that are still felt today. From changing the political map to social and economic changes, all of this shows that World War I was a turning point in human history.