Noun, German. Lit. transl. "Lightningwar".
Characteristics of this way of fighting are identification of decisive weak points, intense concentration of all-arms fire thereon, exercise of considerable freedom of action at very junior levels of command, senior commanders deploying well forward (often taking personal command of key leading elements), and rapid exploitation of success, leading to deep armoured penetration into the enemy's rear, collapsing the C2 and morale of the enemy and leading to rout.
These tactics originated in the British Army of WW1 (best known serving advocate was General JFC 'Bony' Fuller) and can be seen, in an early form in the '100 days' of fighting on the Western Front from August to November 1918, when the British threw off a major German advance (Der Kaiserschlacht) and drove the Germans back to the Rhine.
The approach was publicised by Fuller and Capt (ret'd) Basil Liddell-Hart between the wars, and caught the attention of Heinz Guderian, who became its best known exponent. Spam General George Patton also practiced lightning war with his 3rd Army in 1944. On the British part it seems, paradoxically almost, to have been an approach at odds with the prevailing military culture, and did not again receive any serious attention as a way of operating, until the 1980s, culminating with the formal adoption of the doctrine of 'Manoeuvre Warfare' in 1989.
The rapidity of Blitzkrieg demands quick decision making and a style of command that is inherently very flexible, while the nature of deep penetration tactics calls for very low levels of risk-aversion among commanders. It admirably suited a German military culture that had systematically evolved Auftragstaktik (literally Mission Tactics) since Napoleonic times. There is an argument that British command culture (manifested as a Montgomery-like preference for 'tidy' battles, and an inclination to over-control) remains fundamentally at odds with the requirements of this kind of fighting.
Arguably only 2 armies can truly be said to have successfully combined all of these characteristics; the Wehrmacht in WW2, and - ironically - the Israeli Defence Force in 1956, 1966 and 1973, although some authorities contend that the coalition victories in the Gulf Wars of 1991 and 2003 were achieved by the application of the same approach.