The M1 Bazooka is an American anti-tank rocket launcher developed by the U.S. Army and approved for service in 1940, the M1 Bazooka was the first of its kind: using a rocket (rather than an anti-tank rifle or a handheld grenade) to shoot a shaped charge at enemy tanks. The Bazooka saw extensive use on all fronts of the war, used against enemy bunkers, pillboxes, fortified positions, and even tanks.
After the disastrous Battle of Kasserine Pass in early 1943, many examples of the Bazooka fell into German hands. Impressed with the innovative idea, the Germans copied the Bazooka wholesale, enlarging the rocket and adding a shield to the tube to protect the shooter from backblast, calling the new weapon the panzerschreck, or "tank terror".
The name "Bazooka" originated from its shape, which bears similarity to the tubular musical instrument invented and popularized by U.S. radio comedian Bob Burns in the 1930s. It is now used as a generic term for any manner of tube-like shoulder-fired rocket launcher, but that's not what this Danbooru tag should be used for. This tag specifically covers the original M1 Bazooka model; for a generic rocket launcher, use rocket launcher tag instead.
