How did Germany use its blitzkrieg ("lightning war") strategy to achieve major victories in the first few months of World War II?

It helped them achieve major victories because it made Britain weak and helped keep them away from Germany

German used new tactics, nobody else had seen and that came as a major advantage. Blitzkrieg tactics required the concentration of offensive weapons (such as tanks, planes, and artillery) along a narrow front. Blitzkrieg surprised the enemy forces with the speed and superiority in fight strategy and firepower.