Answer:
The First World War, also known as World War I, was fought primarily in Europe from 1914 to 1918. It involved the Allied Powers, including France, Russia, and the United Kingdom, and the Central Powers, including Germany and Austria-Hungary. The conflict began with the assassination of Archduke Franz Ferdinand of Austria-Hungary and his wife, and quickly escalated into a full-scale war.
One reason why much of the war had little territorial gain on either side is that it was fought primarily in a series of trench-based battles. The use of trenches, machine guns, and other modern weapons made it difficult for either side to make significant advances on the battlefield. Both sides also had access to similar technologies and resources, which helped to balance the fight.
Additionally, the war was fought between two large and well-equipped coalitions, which made it difficult for either side to gain a decisive advantage. Both sides were able to replace losses and maintain their military strength, which helped to prevent either side from gaining a decisive victory.
Finally, the political and economic goals of the war were often not clearly defined, which made it difficult for either side to achieve a clear victory. The war ended with the signing of the Treaty of Versailles, which brought an end to the conflict but did not result in significant territorial gains for either side.