The "qiblah wall" is usually at the other side of the entrance to the prayer hall. This wall is specially decorated. In a properly sited mosque, it will be set perpendicular to a line leading to Mecca. People pray in rows parallel to the "qiblah" wall. They arrange themselves so they face Mecca. In the "qiblah" wall, usually at its center, is the "mihrab", a niche or depression showing the direction of Mecca. The "mihrab" serves as the place where the imam leads the five daily prayers.
All people must wash themselves before they pray. Mosques often have fountains or other facilities for washing in their entrances or courtyards, so that people can perform the washing ritual before prayer.
At very small mosques, worshippers may use restrooms for their ritual washing, or wu'du. In traditional mosques, there is often a building specially for washing. This is often in the center of the courtyard. In the prayer halls, people must not wear shoes for much the same reason.
Modern mosques should appeal to the community they serve. For this reason, other facilities may also be available at the mosque, like health clinics, libraries, and sports halls.
There may be decorative tiles, plaster or coloured mosaics on the walls. There are no pictures or statues.
Adult Muslims are expected to pray five times a day. Most mosques have formal prayers for each of these times. If performing the prayer is difficult, for example for ill people, then exceptions are made.
Mosques also hold a special prayer service, called "jumuah". This is done once a week. It is a form of Sabbath and replaces the Friday prayers at the mosque. Daily prayers can be done anywhere. However, Muslims are expected to do their Friday prayer at the mosque.
When a Muslim dies, a funeral prayer is normally held. It is held outdoors in a courtyard or square close to the mosque. The prayers have all the worshippers present, including the imam, taking part. During eclipses, mosques will host special prayers called eclipse prayers.
There are two large holidays ("Eids") in the Islamic calendar. During these days, there are special prayers at mosques in the morning. Larger mosques will normally hold them for their own communities as well as the people from smaller local mosques. Mosques, especially those in countries where Muslims are the majority, will also host "Eid" prayers outside in courtyards or town squares.
There are many events in "Ramadan", Islam's holiest month. During "Ramadan", Muslims must fast during the day. Mosques organise "iftar" dinners after sunset. These are done after the fourth required prayer of the day. Part of the food is given by members of the community, which creates nightly potluck dinners. The community contribution to these dinners is required. For this reason, mosques with smaller communities may not be able to hold the "iftar" dinners daily.
Some mosques will also hold meals in the morning before dawn. Mosques will often invite poorer members of the community to these meals. Islam sees giving charity during Ramadan as good acts.
Larger mosques sometimes offer special, optional prayers. They are done after the last required prayer of the day. During each night of prayers, one member of the community who has memorized the entire Qur’an will recite a part of the book. It can last for up to two hours. Sometimes, several such people (not necessarily of the local community) take turns to do this. During the last ten days of Ramadan, larger mosques will host all-night programs to observe "Laylat al-Qadr". It is the night Muslims believe that the Islamic prophet Muhammad first received Qur'anic revelations. On that night, between sunset and sunrise, mosques employ speakers to teach the worshipers about Islam. Mosques or the community usually provide meals at times through the night.
During the late twentieth century, more and more mosques have been used for political purposes. Modern-day mosques in the Western world want to educate good citizens. The details differ greatly from mosque to mosque and from country to country.
Countries with small Muslim populations use mosques as a way to support civic participation. They are more likely to do this than Muslim-majority countries of the Greater Middle East. American mosques host voter registration and civic participation drives. In the United States, Muslims are often immigrants, or the children of immigrants. Mosques want to interest these people for politics. They also want to keep them informed about issues that concern the Muslim community. People who attend the services at the mosque regularly are more likely to take part in protests, to sign petitions, and to involve themselves in political matters.
A link between political views and mosque attendance can still be seen in other parts of the world. After the al-Askari Mosque bombing in February 2006, imams and other Islamic leaders used mosques and Friday prayers to call for calm and peace during the widespread violence.
Beginning in the late twentieth century and continuing into the early twenty-first century, a small number of mosques have also become a base for extremist imams to support terrorism and extreme Islamic ideals. Finsbury Park Mosque in London is a mosque that has been used in this manner.
Like other places of worship, mosques can be at the center of social conflicts.
Babri Mosque was the centre of such a conflict up until the early 1990s when it was demolished. Before a solution could be found, the mosque was destroyed by about 200,000 Hindus. It took place on 6 December 1992. The mosque was built by Babur to mark the birthplace of Ram. It was believed to be on a site of an earlier Hindu temple. The conflict over the mosque was directly linked to rioting in Bombay (present-day Mumbai) as well as bombings in 1993 that killed 257 people.
In February 2006, a bombing seriously damaged Iraq's al-Askari Mosque. This increased the existing tensions. The conflict between two Muslim groups in Iraq had already led to other bombings. However mosque bombings are not limited to Iraq. In June 2005, a suicide bomber killed at least 19 people at an Afghan mosque. In April 2006, there were two explosions at India's Jama Masjid.
After the September 11 attacks, several American mosques were targets of attacks. These ranged from simple vandalism to arson.
The Jewish Defense League was suspected of plotting to bomb the King Fahd Mosque in Culver City, California. There were similar attacks in the United Kingdom after the 7 July 2005 London bombings. Outside the Western world, in June 2001, the Hassan Bek Mosque was the target of attacks. The attacks involved hundreds of Israelis angry at Arabs for a previous attack.
Saudi involvement in building mosques around the world only goes back to the 1960s.
In the 1980s, the Saudi Arabian government began to pay for the building of mosques in countries around the world. An estimated US$45 billion has been spent by the Saudi Arabian government for mosques and Islamic schools in foreign countries. "Ain al-Yaqeen", a Saudi newspaper, reported in 2002 that Saudi money may have helped to build as many as 1,500 mosques and 2,000 other Islamic centers. Saudi citizens have also given a lot of money to mosques in the Islamic world, especially in countries where they see Muslims as poor and oppressed. Following the fall of the Soviet Union, in 1992, mosques in Afghanistan received money from Saudi citizens. The King Fahd Mosque in Culver City, California and the Islamic Cultural Center of Italy in Rome are two of Saudi Arabia's largest investments in foreign mosques as former Saudi king Fahd bin Abdul Aziz al-Saud gave US$8 million and US$50 million to the two mosques, respectively.