World War 1 (WW1) was a huge war that occurred in Europe that began during the summer of 1914. The fighting ended in November of 1918. There were two sides - the Central Powers (Triple Alliance) consisted of the German Empire, Italy, and Turkey. The other side was called the Allied Powers (Triple Entente) consisted of France, Russian Empire, and Great Britain. The war was caused by three factors - Imperialism (the building of empires), Nationalism (strong feelings of deep loyalty to one's people and homeland), and Militarism (the buildup of armies and navies). Along with these factors the assassination of Archduke Franz Ferdinand triggered the war. On June 28,1914 a young Serbian extremenlist, Gavrilo Principe assassinated the heir to the Austrian throne. Many demands and fighting began the first world war - Austria-Hungary made a number of demands on Serbia, on august 1,1914 Austria-Hungary declared war on Serbia. Germany came to Austria's aid. France and Russia began to prepare for war to support their ally, Serbia. Germany declared war on France and Russia. Germany then attached Belgium and Great Britain declared war on Germany. Countries started putting up posters for men to join their forces.
The development of Tanks in World War 1 begain as a solution to the stalemate (both sides unable to advance). The first prototype of the Mark 1 tank (Canadian tank) was tested for British Army on September 8,1915. The British Army called tanks Land Ships, initial vehicles were referred to as Water - Carriers (then shortened to Tanks for secrecy. 
The airplane was just getting started in World War 1, therefore very new technology of the time. At the beginning of the war planes were used for surveying enemy territory and so pilots would report their findings of enemy movement so the aim of artillery guns could be adjusted to be more effective. Later planes were equipped for combat with other planes. They attached ground forces with machine guns and bombs, and also bombed submarines at the surface. Airplanes of World War 1 were mostly made of hard wood (braced with steel wires), dipped in a flammable liquid to give them stiffness required to form a wing surface. One of the most famous pilots of World War 1 was the RED BARON, a German flying ace. 
In World war 1 many guns and artillery were just muskets and cannons that shot metal balls out of them. There weren't just guns and artillery but there were bombs to which came down and took out soldiers in groups from aircraft.
