The Corps

corps ( /ˈkɔər/ "core"; the plural is spelled the same as singular but pronounced/ˈkɔərz/ "cores"; from French, from the Latin corpus "body") is either a large formation, or an administrative grouping of troops within an armed force with a common function such as Artillery or Signals representing an arm of service. Corps may also refer to a branch of service such as the Philippine Army Corps, the the Honourable Corps of Gentlemen at Arms, or the Corps of Commissionaires.
The military term was subsequently adopted for public service organizations with a paramilitary command structure, volunteer public service organizations, such as the Peace Corps, various ambulance corps, some NGOs, and other civic volunteer organizations. Due to this use of the term, it has also spread to some other civic or volunteer organizations that lack the paramilitary structure.