World War I, which lasted from 1914 to 1918, was one of the largest conflicts in human history. This conflict involved many countries in Europe and outside Europe, triggering radical changes in global political, social and economic structures. As a direct result of rivalries between major powers, military alliances, and nationalistic tensions, these wars changed the world map and shaped the modern world as we know it today. One of the main causes of World War I was imperialist competition between the great powers, such as England, France, Germany, and Austria-Hungary. Tensions increased with the emergence of defensive alliances, such as the Triple Entente (France, Britain, and Russia) and the Triple Alliance (Germany, Austria-Hungary, and Italy). When the assassination of Archduke Franz Ferdinand of Austria on June 28, 1914 erupted, a rapid series of events made war a reality. The social impact of World War I was profound. This war caused millions of deaths and injuries, and created collective trauma in the countries involved. There is not only a significant physical toll, but also changes in gender roles. Women began to take important roles in the workplace, replacing men who went to war, and this was the first step towards the women’s rights movement. Politically, World War I resulted in major changes in global power. The collapse of the Austro-Hungarian and Ottoman empires led to the formation of new states, establishing new political maps in Europe and the Middle East. Meanwhile, the Bolshevik Revolution in Russia introduced communist ideology, which later became a major challenge to capitalism throughout the world. The world economy is also undergoing a major transformation. The consequences of the war caused many countries to experience high inflation and debt. The US economy, in turn, grew rapidly as a result of demand for weapons and war supplies. The factor is the transition from Europe as the center of the world economy to the United States. World War I also introduced modern weapons and warfare techniques, resulting in permanent changes in military tactics. Trench warfare, chemical weapons, and the use of tanks became common strategies used in the conflict, taking the fighting to a more brutal dimension. This tactical influence continued to be felt into World War II and subsequent modern conflicts. The end of World War I was marked by the Treaty of Versailles, which not only ended the war but also established strict peace terms for the defeated nations. These harsh sanctions against Germany contributed to the political and economic instability that would give rise to World War II. Overall, the impact of World War I was far-reaching and profound. From shifts in political power and social change, to the evolution of the global economy and warfare technology, all of these factors shape the modern world. Every aspect of life today, from foreign policy to gender roles, has its roots in this game-changing conflict, making it one of the most important chapters in world history.