The Triple Entente was an informal agreement between Britain, France, and Russia. It was formed in 1907 and was designed to counter the growing power of Germany and Austria-Hungary.
The Triple Alliance was a formal agreement between Germany, Austria-Hungary, and Italy. It was formed in 1882 and was designed to protect Germany from a potential attack by France and Russia.
In 1914, the assassination of Archduke Franz Ferdinand of Austria sparked a chain of events that led to the outbreak of World War I. Germany declared war on Russia, and France declared war on Germany in support of Russia. Britain declared war on Germany in response to the invasion of Belgium.
The war lasted for four years and resulted in the deaths of millions of people. It ended with the armistice of 1918, which led to the collapse of the German Empire and the establishment of the Weimar Republic.