What were the 4 trenches used by the allies?

4 of the trenches used by the Allies were, the front-line trench, support trench, reserve trench and the communications trenches.

[1] The first were the "front line trenches", where most of the fighting took place in these trenches.

[2] Behind the front line trenches were "support and reserve trenches". These served as homes to the soldiers who had come back from the front line.

[3] The last trenches were the "communication trenches". These were used to transport men, food, water, and supplies.