Clones

The Grand Army of the Republic (GAR), created by Kaminoan cloners on the planet Kamino, initially comprised 200,000 clone troopers and thousands of combat vehicles. The army's ranks were subsequently swelled by over a million more clones.

There were different types of clones, for example:
The clone trooper was a standard combat unit, the Republic's primary military unit. They were used to destroy large groups of droids.
A clone pilot is a clone trooper trained to pilot vehicles. Unlike other clones, he was not trained for combat, but carried a compact blaster pistol.
Clone commandos were an elite unit designed for special operations. They had enhanced free will, unlike other clones.
A clone shadow was an elite unit of the Grand Army of the Republic, tasked with reconnaissance and sabotage behind enemy lines. They typically operated in squads of two or three fighters.

After the Clone Wars, the GAR ceased to exist and was reorganized into the army of the Galactic Empire.