|“||In a hole in the ground there lived a hobbit. Not a nasty, dirty, wet hole, filled with the ends of worms and an oozy smell, nor yet a dry, bare, sandy hole with nothing in it to sit down on or to eat: it was a hobbit-hole and that meant comfort.||”|
–Description of a Hobbit-hole
They were holes dug into the hill side, usually having a minimum of one round window and front door and sometimes back door. It was the primarily wealthy families of Hobbits built Smials, spacious and luxurious tunnels, a souped up version of a Hobbit-hole. Brandy Hall is an example of a Smial and had three front doors, many side doors and around one hundred windows. Bag End, the home of Bilbo Baggins and later Sackville-Bagginses and then Sam Gamgee, could be called a Smial, as it was an expansive Hobbit-hole with many windows; a large circular green front and back door, and a large number of rooms; as well as the famously renowned pantries which supplied food for many a party or celebration.
On the other hand, the poor lived in basic burrows with perhaps only a single window. An example of this is Bagshot Row. The famous Took family lived in the Great Smials, their ancestral home and many-tunneled mansion.