Almost all 1B+ residence will have a den in the unit. This is not common, especially in apartments, but a den will serve as an important room for someone that would be organized enough to understand the potential. Even though most people likely have a notebook PC, it is ideal to have a “home base” for their computer. Also, if there is a printer, placing that printer in the den just makes sense as it will not be located in the great/living room. The den can also host a desktop NAS? which will provide for backups, and additional LAN? storage.
Some people might be asking why not make the den a bedroom? Two reasons, the closet in the den is too small for a suitable bedroom closet. In addition, there is only 1 means of egress. For fire reasons, each bedroom must have 2 means of egress. This is in case the fire is blocking the primary means, there is a possibility to get rescued from the fire deparment. This simply can not happen in an den.