World War I involved one group of countries fighting another.
The Central Powers ( Mittelmächte Központi hatalmak İttifak Devletleri or Bağlaşma Devletleri Централни сили Tsentralni sili ) , consisting of Germany , , the Ottoman Empire and Bulgaria -- hence also known as the Quadruple Alliance ( Vierbund ) -- was one of the two main factions during World War I ( 1914 -- 18 ) . The Paris Peace Conference , also known as Versailles Peace Conference , was the meeting of the Allied victors , following the end of World War I to set the peace terms for the defeated Central Powers diplomats from more than 32 countries and nationalities . Triple Entente . At the start of World War I in 1914 , all three Triple Entente members entered it as Allies of World War I against the Central Powers , Germany and Austria-Hungary . World War I ( WWI or WW1 ) , also known as the First World War , the Great War , or the War to End All Wars , was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918 . A world war , as it is commonly understood , is a large-scale war involving many of the countries of the world or many of the most powerful and populous ones .