Guerrilla warfare is a form of irregular warfare that involves small, mobile groups of combatants using tactics such as ambushes, sabotage, and hit-and-run attacks against larger traditional forces. This method is particularly effective in environments where the home advantage and local knowledge can offset the enemy's superior resources and numbers. It played a crucial role during conflicts like the War of 1812, where both British and American forces faced challenges from irregular fighters using unconventional strategies.