A mosque is a space dedicated to religious worship, prayer, and services by adherents to the Islamic faith. Mosques are usually located in mosque buildings, but they can also be found sometimes in other types of structures such as low-rise buildings. Mosques can have a particular Sunni, Shia, or other Islamic affiliation, while adherents of different traditions may also use the same space for worship.

The space is dedicated to Islamic religious practice. A Muslim community can also have offices or social rooms whose functions are separate from worship and prayer.

A mosque building is a particular physical form, while a mosque as a worship space can occupy a converted structure. The converted building need not have been designed as a mosque.