A common room is a group into which students are organised in some universities, particularly in the United Kingdom, normally in a subdivision of the university such as a college or hall of residence, in addition to an institution-wide students' union. They represent their members within the hall or college, operate certain services within these institutions such as laundry or recreation, and provide opportunities for socialising. There are variations based on institutional tradition and needs, but classically the following common rooms will exist:A junior common room (JCR) – for undergraduate students
A middle common room (MCR) – for post-graduate students
A senior common room (SCR) – for academic members of the college