A mosque is a prayer hall, also known as the musalla, has no furniture; chairs and pews are absent from the prayer hall so as to allow as many worshipers as possible to line the room. Some mosques have Arabic calligraphy and Qur'anic verses on the walls to assist worshippers in focusing on the beauty of Islam and its holiest book, the Qur'an, as well as for decoration.
Usually opposite the entrance to the prayer hall is the qiblah wall, the visually emphasized area inside the prayer hall. The qiblah wall should, in a properly oriented mosque, be set perpendicular to a line leading to Mecca, the location of the Kaaba.
Congregants pray in rows parallel to the qiblah wall and thus arrange themselves so they face Mecca. In the qiblah wall, usually at its center, is the mihrab, a niche or depression indicating the direction of Mecca. Usually the mihrab is not occupied by furniture either. Sometimes, especially during Friday prayers, a raised minbar or pulpit is located to the side of the mihrab for a khatib or some other speaker to offer a sermon (khutbah). The mihrab serves as the location where the imam leads the five daily prayers on a regular basis