Imperial Stormtroopers (Star Wars) are soldiers in the Star Wars franchise created by George Lucas. They acted as the shock troops of the main antagonists of the saga, the Galactic Empire, as well as the main fighting force for the Empire. They were identified as wearing white and black armor. In the Prequel Trilogy, it is revealed that they were descendants of the Clone Troopers from the Clone Wars. The overall branch they belonged to was called the Stormtrooper Corps, independent from the rarely seen soldiers from the Imperial Army. Their effectiveness is downplayed in the movies when fighting the main characters, since the main characters have plot armor (a term used for main characters not being allowed to die), although in-universe, at least regarding the first film, it is implied that they deliberately missed the main characters specifically to have them unwittingly lure them to the secret Rebel Base.
Prior to the Disney acquisition, the Stormtroopers in the Expanded Universe were their own military branch separate from the Army and Navy branches of the Empire acting as shock troopers, while after the acquisition, the Stormtroopers were considered an elite part of the Imperial Army.
Stormtroopers were also used for the successor group of the Empire in the Sequel Trilogy called the First Order. Their overall appearance was similar to the original film, although the helmets had a different design.
They were named after the Stormtruppen from World War I, and shared a similar role to them regarding breaching Rebel strongholds in various Expanded Universe materials. They also were analogous to various other groups, including the Waffen-SS Leibstandarte SS Adolf Hitler (LSSAH) (due to operating outside the standard hierarchy and being loyal to Emperor Palpatine directly), the United States Marine Corps (due to aiding both the Army and Navy in various operations), and U.S. Army Rangers (due to the Legacy era of the Legends EU having them being subordinate elite units to the Imperial Army). Despite sharing a similar name to the Sturmabteilung in Nazi Germany, however, there's little indication that they were based on that group.