I was suggested to post this question here by the Sabaton History patreon as I did not know where else to post.
I am deeply curious about how the front lines of war (be it World War 2 or another major conflict) would look as a whole from the ground. In animations for Sabaton History, The Great War Week by Week, World War 2 Day By Day, armies are shown along the entire front as you would imagine.
However, were there men on every foot of the front? Were the armies stationed only on certain fortified points along the front, with other parts of it that looked devoid of human life? I know in ancient times, it was the latter - and that on the Western Front of WW1, it was likely the former. But in general, what did the front lines look like?