The Sith Order bestows a number of titles upon its followers, as befits their rank and power. These are the most common:
Acolyte: A Sith acolyte has not yet completed his or her trials in the Sith Academy, and may well die before becoming truly “Sith.”
Sith: An acolyte who completes the trials and is accepted as the apprentice of a Sith Lord is considered Sith‒no more, no less. Any non-Sith, however, is expected to refer to a Sith as “my lord” out of respect.
Overseer: An instructor at the Sith Academy is called an overseer. Overseers are often Sith Lords, but that rank is not a requirement; they may simply be Sith with a talent for instruction.
Sith Lord: A Sith who advances in the order's hierarchy will eventually be elevated to Sith Lord. His or her name is preceded by “Lord” in formal address. In the modern Empire, “Dark Lord” is synonymous with this term.
Darth: The strongest Sith Lords ascend to the position of Darth. Many take a new name at this point, symbolically embracing their transformation into something greater.
Emperor: There has been only one Sith Emperor since the Great Hyperspace War over 1,300 years ago. He is supreme.