(Lat. oratorium, “place of prayer”). From its more general original meaning, the term is now associated in
(1) A public oratory, chiefly for private individuals or a community, but open to all worshipers at least when divine services are held.
(2) A semi-public oratory is designed for the use of a particular community which may, however, at its pleasure admit or exclude others.
(3) A private or domestic oratory (the adjectives were previously distinguishable but are now virtually interchangeable) is set up in a private home for the use of a family or individual. In such instances they are a reversion to historical usagei.e., places of prayer which are no substitute for the local churches and are used only exceptionably for Mass.