Commerce raiding is a form of naval warfare used to destroy or disrupt logistics of the enemy on the open sea by attacking its merchant shipping, rather than engaging its combatants or enforcing a blockade against them. Privateering is a form of commerce raiding conducted by independent operators.
HINT:
In this Dossier
Commerce raiders in the context of U-boat Campaign (World War I)
The U-boat campaign from 1914 to 1918 was the World War I naval campaign fought by German U-boats against the trade routes of the Allies, largely in the seas around the British Isles and in the Mediterranean, as part of a mutual blockade between the German Empire and the United Kingdom.
Both Germany and Britain relied on food and fertilizer imports to feed their populations, and raw materials to supply their war industry. The British Royal Navy was superior in numbers and could operate on most of the world's oceans because of the British Empire, whereas the Imperial German Navy surface fleet was mainly restricted to the German Bight, and used commerce raiders and submarine warfare to operate elsewhere.
View the full Wikipedia page for U-boat Campaign (World War I)