The first world was was primarily fought against who?

The First World War, also known as World War I, primarily involved the Allies and the Central Powers. The main countries in the Allies included France, the United Kingdom, Russia, and later the United States, while the Central Powers were led by Germany, Austria-Hungary, the Ottoman Empire, and Bulgaria. The war began in 1914 and was sparked by the assassination of Archduke Franz Ferdinand of Austria, leading to a complex web of alliances and conflicts.