What was the relationship between world war i and world war ii, and how did the ways in which the wars were fought differ?

Well one relationship would be Hitler fought in both of them for one. They differ because Hitler was a General In WW2 and he was a soldier in WW1. Umm... In WW2, thousands of prisoners were killed in camps, and in WW1 there was not.
(I am pretty sure, I am going off of memory here)
They were also fought differently because there were two different presidents during both wars.
In WW2 was the first base we had ever had bombed, ever in WW1 we didn’t.
There are some similarities and differences there. Hope this helps?