During WWI, one of the reasons it became known as “The Great War” was because of how many warring nations were involved in the conflict. Another reason had to do with the amount of new weapons that had formed in the previous 20 years up until the time of the war. Below is several links to a website describing some of the different technologies that were either invented or improved greatly during the time of WWI.
1.) Flame throwers: http://www.firstworldwar.com/weaponry/flamethrowers.htm
2.) Grenades: http://www.firstworldwar.com/weaponry/grenades.htm
3.) Machine Guns: http://www.firstworldwar.com/weaponry/machineguns.htm
4.) Poison gases: http://www.firstworldwar.com/weaponry/gas.htm
5.) Upgraded Rifles: http://www.firstworldwar.com/weaponry/rifles.htm
6.) Mortars: http://www.firstworldwar.com/weaponry/mortars.htm
That is just a simple listing of weapons that were greatly upgraded to suit the new type of combat and trench warfare that would fall upon many troops. Above are detailed descriptions, including how the weapons were used and such. In another post I will focus among other new technologies that COMPLETELY changed WWI: Airplanes and Tanks.