The short answer
A derb is a medina lane, often a dead end, and the small community that lives along it. A traditional medina quarter includes a mosque, a Quranic school, a hammam, a fountain and a ferran, the public bread oven. Doors are plain on the outside and life happens inside, round a courtyard. Your riad is almost certainly on one.
In more detail
Derbs are residential, not tourist streets. Children play football in the lane and neighbours greet every passer-by. Walk through quietly, return greetings with 'salam', and do not photograph people or open doorways without asking.
Because many derbs are dead ends, they are where visitors most often get lost. A friendly stranger who offers to lead you out may expect payment. Save your riad's location on your phone, or ask your riad to meet you at a landmark.
Dress for a neighbourhood: shoulders and knees covered. The derbs are where the medina's modesty norms matter most, more than in the busy souk lanes.
Many derbs keep their communal bread oven, the ferran, where children and women bring trays of shaped dough under a cloth and the baker slides them onto hot bricks with a long wooden paddle. It is a working part of the neighbourhood, so ask before you photograph it.
Good to know
- Return greetings as you pass.
- Save your riad's location offline.
- Keep voices low late at night; people live here.