The house system is the basis of undergraduate student residence at the California Institute of Technology (Caltech). Caltech's unique house system is modeled after the residential college system of Oxford and Cambridge in England, although the houses are probably more similar in size and character to the Yale University residential colleges and Harvard University house system. Like a residential college, a house embodies two closely connected concepts: it serves as both a physical building where a majority of its members reside and as the center of social activity for its members.