From the One Wiki to Rule Them All, the Lord of the Rings Encyclopedia.
Bag-end, a high end hobbit hole
A collection of hobbit-holes
Hobbits preferred to dwell in holes called
Hobbit-holes; they felt most at home in underground tunnels. Their belief was that all Hobbits had once dwelt underground but by the time of the
War of the Ring, it was primarily the very wealthy and the very poor who did so. The wealthy built luxurious tunnels, called "smials."
Brandy Hall, as an example, had three front doors, many side doors, and around a hundred windows.
Bag End, home of
Bilbo Baggins and
Frodo Baggins could be called a smial. The
Took family lived in the
Great Smials. On the other hand, the poor lived in basic burrows, with perhaps only a single window. Hobbit-holes usually had round windows and doors.