well I’ll help you out a little, but you should google it.
The main difference is that in ww1 they used trench warfare. The invention of the machine gun caused millions of people to die. Now that thousands of people could die in a single battle. The area between 2 trenches is called no mans land. They sent thousands of people over the top of the trenches to storm the enimy, but when they did they were killed by the machine guns.
In ww2 germany was pissed that they had to pay for ww1. We really haven’t gotten to the core of ww2 yet
Ohh and what basically ended ww1 was tanks. The British came up with the idea and started working on them. They moved very slow and broke down quite often. But when they did get to the trenches it was devistating. They did not have the huge gun on them, just machine guns that where on the sides to shoot the people in the trenches.