Blitzkrieg
Every unit in the army, from the company to the supreme command, decided on a Schwerpunkt by schwerpunktbildung, as did the support services, which meant that commanders always knew what was the most important and why. The German army was trained to support the Schwerpunkt even when risks had to be taken elsewhere to support the point of main effort and to attack with overwhelming firepower. Schwerpunktbildung allowed the German Army to achieve superiority at the Schwerpunkt, whether attacking or defending, to turn local success at the Schwerpunkt into the progressive disorganisation of the opposing force and to create more opportunities to exploit that advantage even if the Germans were numerically and strategically inferior in general. In the 1930s, Guderian summarized that as Klotzen, nicht kleckern! ("Kick, don't spatter them!")

Pursuit: Having achieved a breakthrough of the enemy's line, units comprising the Schwerpunkt were not supposed to become decisively engaged with enemy front line units to the right and the left of the breakthrough area. Units pouring through the hole were to drive upon set objectives behind the enemy front line. During the Second World War, German Panzer forces used their motorized mobility to paralyze the opponent's ability to react. Fast-moving mobile forces seized the initiative, exploited weaknesses and acted before the opposing forces could respond. Central to that was the decision cycle (tempo). Through superior mobility and faster decision-making cycles, mobile forces could act faster than the forces opposing them.
Directive control was a fast and flexible method of command. Rather than receiving an explicit order, a commander would be told of his superior's intent and the role that his unit was to fill in that concept. The method of execution was then a matter for the discretion of the subordinate commander. The staff burden was reduced at the top and spread among tiers of command with knowledge about their situation. Delegation and the encouragement of initiative aided implementation, and important decisions could be taken quickly and communicated verbally or with only brief written orders.

Mopping-up: The last part of an offensive operation was the destruction of unsubdued pockets of resistance, which had been enveloped earlier and bypassed by the fast-moving armored and motorized spearheads. The Kesselschlacht ("cauldron battle") was a concentric attack on such pockets. It was there that most losses were inflicted upon the enemy, primarily through the mass capture of prisoners and weapons. During Operation Barbarossa, huge encirclements in 1941 produced nearly 3.5 million Soviet prisoners, along with masses of equipment.

Air power: Close air support was provided in the form of the dive bomber and medium bomber, which would support the focal point of attack from the air. German successes are closely related to the extent to which the German Luftwaffe could control the air war in early campaigns in Western and Central Europe and in the Soviet Union. However, the Luftwaffe was a broadly based force with no constricting central doctrine other than its resources should be used generally to support national strategy. It was flexible and could carry out both operational-tactical, and strategic bombing.
Flexibility was the strength of the Luftwaffe in 1939 to 1941. Paradoxically, that became its weakness. While Allied Air Forces were tied to the support of the Army, the Luftwaffe deployed its resources in a more general operational way. It switched from air superiority missions to medium-range interdiction, to strategic strikes to close support duties, depending on the need of the ground forces. In fact, far from it being a specialist panzer spearhead arm, less than 15 percent of the Luftwaffe was intended for close support of the army in 1939.

Stimulants: Methamphetamine, known as "pervitin," use is believed to have played a role in the speed of Germany's initial Blitzkrieg since military success with combined arms demanded long hours of continuous operations with minimal rest.

Limitations and countermeasures: 

Environment: The concepts associated with the term blitzkrieg (deep penetrations by armor, large encirclements, and combined arms attacks) were largely dependent upon terrain and weather conditions. Wherever the ability for rapid movement across "tank country" was not possible, armored penetrations often were avoided or resulted in failure. The terrain would ideally be flat, firm, unobstructed by natural barriers or fortifications, and interspersed with roads and railways. If it were instead hilly, wooded, marshy, or urban, armor would be vulnerable to infantry in close-quarters combat and unable to break out at full speed. Additionally, units could be halted by mud (thawing along the Eastern Front regularly slowed both sides) or extreme snow. Operation Barbarossa helped confirm that armor effectiveness and the requisite aerial support depended on weather and terrain. The disadvantages of terrain could be nullified if surprise was achieved over the enemy by an attack in areas that had been considered natural obstacles, as occurred during the Battle of France in which the main German offensive went through the Ardennes. Since the French thought that the Ardennes unsuitable for massive troop movement, particularly for tanks, the area was left with only light defences, which were quickly overrun by the Wehrmacht. The Germans quickly advanced through the forest and knocked down the trees that the French had thought would impede them.

Air superiority: The influence of air forces over forces on the ground changed significantly over the course of the Second World War. Early German successes were conducted when Allied aircraft could not make a significant impact on the battlefield. In May 1940, there was near parity in numbers of aircraft between the Luftwaffe and the Allies, but the Luftwaffe had been developed to support Germany's ground forces, had liaison officers with the mobile formations and operated a higher number of sorties per aircraft. In addition, the Germans' air parity or superiority allowed the unencumbered movement of ground forces, their unhindered assembly into concentrated attack formations, aerial reconnaissance, aerial resupply of fast moving formations and close air support at the point of attack. The Allied air forces had no close air support aircraft, training or doctrine. The Allies flew 434 French and 160 British sorties a day but methods of attacking ground targets had yet to be developed and so Allied aircraft caused negligible damage. Against the Allies' 600 sorties, the Luftwaffe on average flew 1,500 sorties a day.
On 13 May, Fliegerkorps VIII flew 1,000 sorties in support of the crossing of the Meuse. The following day the Allies made repeated attempts to destroy the German pontoon bridges, but German fighter aircraft, ground fire and Luftwaffe flak batteries with the panzer forces destroyed 56 percent of the attacking Allied aircraft, and the bridges remained intact.
Allied air superiority became a significant hindrance to German operations during the later years of the war. By June 1944, the Western Allies had the complete control of the air over the battlefield, and their fighter-bomber aircraft were very effective at attacking ground forces. On D-Day, the Allies flew 14,500 sorties over the battlefield area alone, not including sorties flown over Northwestern Europe. Against them the Luftwaffe flew some 300 sorties on 6 June. Though German fighter presence over Normandy increased over the next days and weeks, it never approached the numbers that the Allies commanded. Fighter-bomber attacks on German formations made movement during daylight almost impossible.
Subsequently, shortages soon developed in food, fuel and ammunition and severely hampered the German defenders. German vehicle crews and even flak units experienced great difficulty moving during daylight. Indeed, the final German offensive operation in the west, Operation Wacht am Rhein, was planned to take place during poor weather to minimise interference by Allied aircraft. Under those conditions, it was difficult for German commanders to employ the "armored idea", if at all.

Counter-tactics: Blitzkrieg is vulnerable to an enemy that is robust enough to weather the shock of the attack and does not panic at the idea of enemy formations in its rear area. That is especially true if the attacking formation lacks the reserve to keep funnelling forces into the spearhead or the mobility to provide infantry, artillery and supplies into the attack. If the defender can hold the shoulders of the breach, it has the opportunity to counter-attack into the flank of the attacker and potentially to cut it off the van, as what happened to Kampfgruppe Peiper in the Ardennes.
During the Battle of France in 1940, the 4th Armoured Division (Major-General Charles de Gaulle) and elements of the 1st Army Tank Brigade (British Expeditionary Force) made probing attacks on the German flank and pushed into the rear of the advancing armored columns at times. That may have been a reason for Hitler to call a halt to the German advance. Those attacks combined with Maxime Weygand's hedgehog tactic would become the major basis for responding to blitzkrieg attacks in the future. Deployment in depth, or permitting enemy or "shoulders" of a penetration, was essential to channelling the enemy attack; artillery, properly employed at the shoulders, could take a heavy toll on attackers. Allied forces in 1940 lacked the experience to develop those strategies successfully, which resulted in the French armistice with heavy losses, but those strategies characterized later Allied operations.
At the Battle of Kursk, the Red Army used a combination of defence in great depth, extensive minefields and tenacious defense of breakthrough shoulders.