Of all Muslim institutions, the mosque is the most important place for the public expression of Islamic religiosity and communal identity. A mosque is a physical manifestation of the public presence of Muslims and serves as a point of convergence for Islamic social and intellectual activity. The Arabic word for mosque is masjid, which means a "place of prostration" before God. Mosques are mentioned in the Qur'an, and the earliest model for a mosque was the residence that the prophet Muhammad built when he moved to Medina. This first mosque was an enclosure marked as a special place of worship. A small part of the mosque was sectioned off to house the Prophet and his family, and the remaining space was left open as a place for Muslims to pray.
Although later mosques developed into complex architectural structures built in diverse styles, the one requirement of all mosques continues to be based on the earliest model: a designation of space for the purpose of prayer. The early mosque served an equally important function that thousands of mosques continue to serve today: The mosque is a place where Muslims foster a collective identity through prayer and attend to their common concerns. A Muslim city typically has numerous mosques but only a few congregational or Friday mosques where the obligatory Friday noon prayers are performed.
As Islam spread outside Arabia, Islamic architecture was influenced by the various architectural styles of the conquered lands, and both simple and monumental mosques of striking beauty were built in cities of the Islamic world. Despite the borrowings from diverse civilizations, certain common features became characteristic of most mosques and thus serve to distinguish them from the sacred spaces of other religions and cultures.
The most important characteristic of a mosque is that it should be oriented toward Mecca. One or more niches (mihrab) on one of the walls of the mosque often serve as indicators of this direction, called qibla. When the imam leads the prayers he usually faces one of these niches. Next to the mihrab, a pulpit (minbar) is often provided for the delivery of sermons (khutba). Many mosques also have separate areas for performing ritual ablution, and separate sections for women. In many mosques, several rows of columns are used to mark the way for worshipers to line up behind the imam during prayer.
Mosques usually have one or more minarets, or towers, from which the muezzin calls Muslims to prayer five times a day. In addition to their functional use, these minarets have become distinguishing elements of mosque architecture. In large mosques in particular, minarets have the effect of tempering the enormity and magnificence of the domed structure by conveying to the viewer the elevation of divinity above the pretensions of human grandeur.
mosques also have a dome, and the line connecting the center of the dome
to the niche is supposed to point toward Mecca. Throughout the world there
are many mosques that are not actually directed toward Mecca, but such
misalignment is due to inaccurate methods for determining the direction
of Mecca and does not imply a disregard for this requirement. The mosque
is not a self-contained unit, nor is it a symbolic microcosm of the universe,
as are some places of worship in other religions. Rather, the mosque is
always built as a connection with Mecca, the ultimate home of Muslim worship
that metaphorically forms the center of all mosques.