What type of impact did the trench warfare have on history

Trench warfare caused enormous numbers of casualties.

Not surprisingly, this approach was rarely effective, and often led to mass casualties. Later in the war, forces began mounting attacks from the trenches at night, usually with support of covering artillery fire.

Basically improving the way of warfare

It changed the way people thought about war.

Explanation:

During WW1 trench warfare was almost use exclusively, it is an extremly slow form of war. It breaks soldiers done with what they called shell shock (more commonly known as ptsd) because they would just continuesly hear explosions.

Once WW2 started the Germans used lightning ware fare, which is when they strike really fast and precisely. It worked very well, strongly because ww made everyone think that with modern technologies that the only way to fight a war is with trench warfare.