This article lists down the different terminologies used in Toaru Majutsu no Index. This article will cover only basic terminologies and will leave more complicated terms listed on the Terminology Category page.
People who possess psychic abilities. A majority of espers are developed using the Power Development Curriculum of Academy City. Espers who are born with psychic abilities are called Gemstones.
Practicioners of magic. They acquire their abilities by learning about magic and training, and may be identified by using a Magic Name. Most magicians are affiliated to a certain religious group.
The main setting of Toaru Majutsu no Index and Toaru Kagaku no Railgun. A technologically-advanced city located west of Tokyo which consists of various educational facilities.
Books that are infused with immense amounts of magic by their authors. Grimoires can be dangerous even for experienced magicians, and the only one who is able to handle constant exposure to grimoires is Index, who possesses 103,000 grimoires in her head.