A school shooting is an armed attack at an educational institution, such as a primary school, secondary school, high school or university, involving the use of a firearm. Many school shootings are also categorized as mass shootings due to multiple casualties. The phenomenon is most widespread in the United States, which has the highest number of school-related shootings, although school shootings have taken place elsewhere in the world.

Violence is the use of physical force to cause harm to people, non-human animals, or property, such as pain, injury, death, damage, or destruction. Some definitions are somewhat broader, such as the World Health Organization's definition of violence as "the intentional use of physical force or power, threatened or actual, against oneself, another person, or against a group or community, which either results in or has a high likelihood of resulting in injury, death, psychological harm, maldevelopment, or deprivation."