Preachers are common throughout most cultures. They can take the form of a
minister on a Sunday morning, or an Islamic
Imam. A Muslim preacher in general is referred to as a
dā‘ī, while those giving sermons on a Friday afternoon are described as a
The sermon or homily has been an important part of Christian services since Early Christianity, and remains prominent in both
Roman Catholicism and
Lay preachers sometimes figure in these traditions of worship, for example the
Methodist local preachers, but in general preaching has usually been a function of the
Dominican Order is officially known as the Order of Preachers (Ordo Praedicatorum in
friars of this order were trained to publicly preach in
vernacular languages, and the order was created by
Saint Dominic to preach to the
Cathars of southern France in the early thirteenth century. The
Franciscans are another important preaching order; Travelling preachers, usually friars, were an important feature of late medieval Catholicism.
In most denominations, modern preaching is kept below about 40 minutes, but historic preachers of all denominations could at times speak for well over an hour, sometimes for two or three hours,
 and use techniques of
rhetoric and theatre that are today somewhat out of fashion in mainline churches.
In many churches in the United States, the title "Preacher" is synonymous with "
pastor" or "
minister", and the church's minister is often referred to simply as "our/the preacher" or by name such as "Preacher Smith". However, among some Chinese churches, preacher (Chinese: 傳道) is different from pastor (Chinese: 牧師). A preacher refers to the younger clergy in the Protestant church who are not officially recognised as a pastor until they can prove their capability of leading the church.