On the picture: (from left to right) a ‘vaaz kürsüsü’ (= pulpit of the sermon), the ‘mihrab’ and the ‘minber’ .
Above the mihrab the calligraphic inscription quotes the 144th verse of the ‘Surat al-Baqarah’ (the second chapter of the Kuran), which contains recommendations regarding the common prayer.

Mihrab = a semicircular niche in the wall of a mosque that indicates the direction of the Kaaba in Mecca and hence the direction that Muslims should face when praying. The wall in which a mihrab appears is the "qibla wall."
Minber = a (large) pulpit in the mosque where the imam (prayer leader) stands to deliver sermons.
‘Minber’ and ‘vaaz kürsüsü’ are both pulpits, from where sermons are given. The difference is that the minber is obligatory for the ‘Friday sermon’, held during the most important common prayer of Islamic week. All other sermons can be held from the smaller ‘kürsü’.

Correspondent: J.M.Criel, Antwerpen.
Sources: Websites of ‘istanbuldakicamiler.com’ & ‘kuran.diyanet.gov.tr’ .